U.S. Route 21
US 21 highlighted in red
Route information
Maintained by SCDOT, NCDOT, and VDOT
Length	393 mi[1] (632 km)
Existed	November 11, 1926 (1926-11-11)[2]–present
Tourist routes	McTeer Bridge Scenic Byway US 21 Scenic Byway
Major junctions
South end	Hunting Island State Park, SC
Major intersections	I-95 near Yemassee, SC I-26 (three times in SC) I-20 in Columbia, SC I-77 (numerous times in SC/NC) I-85 in Charlotte, NC I-40 in Statesville, NC
North end	I-81 / US 52 in Wytheville, VA
Location
Country	United States
States	South Carolina, North Carolina, Virginia
Counties	SC: Beaufort, Hampton, Colleton, Bamberg, Orangeburg, Calhoun, Lexington, Richland, Fairfield, Chester, York NC: Mecklenburg, Iredell, Yadkin, Surry, Wilkes, Alleghany VA: Grayson, Wythe
Highway system
United States Numbered Highway System List Special Divided
South Carolina State Highway System Interstate US State Scenic
North Carolina Highway System Interstate US State Scenic
Virginia Routes Interstate US Primary Secondary Byways History HOT lanes
← US 20 US → US 22 ← SC 20 SC → SC 22 ← NC 20 NC → NC 22 ← SR 20 VA → SR 22

U.S. Route 21 or U.S. Highway 21 (US 21) is a north–south United States Numbered Highway, spanning 393 miles (632 km) from Hunting Island State Park, South Carolina, to Wytheville, Virginia. The route traverses three states, South Carolina, North Carolina, and Virginia. It connects southeastern cities, including Columbia, South Carolina, and Charlotte, North Carolina.

US 21 starts at Hunting Island State Park, bypasses Beaufort, South Carolina, and then heads north across the low country, paralleling Interstate 77 (I-77) through urban and rural areas before entering North Carolina. In North Carolina, US 21 frequently merges with and splits from I-77. The route enters Virginia, passing through hilly terrain before ending at the intersection of Interstate 81 (I-81) / U.S. Route 52 (US 52) in Wytheville.

Despite the "1" indicating that it is a major north–south highway, US 21 only travels through three states and is no longer a cross-country route, as many sections have been replaced by I-77 in Ohio and West Virginia. Historically, US 21 was longer before the Interstate Highway System was established. US 21 originally ran from Cleveland, Ohio, to Yemassee, South Carolina, it was later extended to Beaufort and Hunting Island State Park. Over time, its length was reduced, making it the second-shortest major north–south route after U.S. Route 91 (US 91).

US 21 serves as an alternative to the more heavily trafficked interstates in the area, particularly I-77, I-26, and Interstate 95 (I-95).

US 21 travels 233.2 miles (375.3 km) through the state. Beginning at Hunting Island State Park, US 21 travels west toward Beaufort, where it widens to four lanes. The route bypasses Beaufort to the south, going through Port Royal, Shell Point, and Burton. In the Beaufort area, US 21 passes by the entrances to Parris Island and Marine Corps Air Station Beaufort, the major Marine Corps installations in the area. North of Beaufort, US 21 continues as a four-lane divided highway and intersects with US 17. The route travels in a wrong-way concurrency with US 17 south for seven miles (11 km) before turning north toward Yemassee, where it becomes a rural two-lane road and intersects with US 17 Alternate. North of Yemassee, US 21 splits off and crosses I-95 at exit 42.

The two-lane route continues through rural portions of the state. US 21 goes through Smoaks and Branchville and bypasses Orangeburg. North of Orangeburg, US 21 runs roughly parallel to I-26 until Gaston where it conjoins US 321 and becomes an urban highway. US 21 passes through Cayce, West Columbia, and Columbia.

North of Columbia, US 21 splits from US 321, reverting to a rural two-lane road parallel to I-77. In York County, US 21 enters urban areas again, connecting Rock Hill and Fort Mill. Near the North Carolina state line, US 21 merges with I-77 near Carowinds, then enters North Carolina.

US 21 begins as a concurrency with I-77 in Charlotte, which it repeats three times within the state. Its first break with I-77 is along Statesville Avenue, then proceeding through Huntersville and Cornelius, however, because of its close proximity to I-77 and North Carolina Highway 115 (NC 115), it has no interchange with I-485 by itself. The second break with I-77 occurs at Mooresville, where US 21 travels through the city and then northwest into Statesville. After Statesville, US 21 travels northeast to Harmony and Brooks Crossroads, before merging back with I-77 near Jonesville. However, Jonesville and Elkin connect with US 21 Bus. through centers of both towns, as an alternate route paralleling I-77. North of Elkin, US 21 splits with I-77 for the last time and goes north to Sparta, passing the Blue Ridge Parkway after a major, curvy section. North of Sparta, at Twin Oaks, US 221 overlaps with US 21 before entering Virginia. US 21 travels 124.5 miles (200.4 km) through the western Piedmont of North Carolina, either combined with I-77 or as a two-lane rural road; from the South Carolina state line to Elkin, travelers can easily skip a majority of US 21 via I-77.

After a few miles crossing the state line, US 21 reaches the town of Independence, where it splits with US 221 and continues north. The route goes through the Mount Rogers National Recreation Area before entering the city of Wytheville. After a short concurrency with US 11 in downtown Wytheville, it goes north and ends at the intersection of I-81/US 52. US 21 travels 35 miles (56 km) through western Virginia, mostly as a two-lane rural mountain road.

US 21 in the pre-Interstate era was a north–south highway connecting the area around Lake Erie and the coastal South. One of the few true north–south routes to cross the middle Appalachian Mountains, it became an important corridor for motor traffic between northeastern Ohio, western Pennsylvania, (with US 19) and western New York with central North Carolina, central and southeastern South Carolina, and (by connecting with other highways) coastal Georgia and most of Florida. Many referred to the stretch of US 21 from the Great Lakes Region to Florida as "The Lakes-to-Florida Highway".

US 21 originally (in 1926) connected Cleveland, Ohio, and Yemassee, South Carolina. In 1935 it was extended to Beaufort, South Carolina, and again in 1953 to its current southern terminus at the Atlantic Coast at Hunting Island State Park, between the city of Beaufort and Fripp Island.^{[3][unreliable source]}

In the Interstate Highway era, much of US 21 became an obvious corridor for a long-distance expressway. The West Virginia Turnpike between Charleston, West Virginia, and Princeton, West Virginia, was the first segment of a planned series of toll highways along or near US 21 from Cleveland to Charlotte, North Carolina. All the other toll highways were shelved in favor of freeways built with Interstate funding; these freeways and the West Virginia Turnpike became I-77, which completely supplanted old US 21 as a long-distance through route. I-77 was later extended to Columbia, South Carolina, also within a few miles of US 21.

Between Cleveland and Charleston, all but a relatively short segment of US 21 was completely deleted in favor of I-77, the relics being as follows:

• State Route 21 (SR 21) between Cuyahoga Heights and Strasburg;^{[citation needed]}
• SR 821 between I-77 near Byesville and SR 60 near Marietta, Ohio;^{[citation needed]}
• County Road 35 (CR 35, Oakwood Road, Byesville Road, Old Twenty-One Road) between Byesville and the Guernsey–Tuscarawas county line;^{[citation needed]}
• CR 3 (Salt Fork Road) between the Guernsey–Tuscarawas county line to SR 258^{[citation needed]}
• CR 21 between Newcomerstown and New Philadelphia^{[citation needed]}
• County Route 21 (CR 21) between Mineral Wells and Charleston.^{[citation needed]}

Between Charleston and its current northern terminus at Wytheville, Virginia, almost all of US 21 ran concurrently with either US 60, US 19, or US 52, which remained as US 21 was deleted. The short segment of US 21 in southern West Virginia not coinciding with another U.S. Highway became an extension of West Virginia Route 16.

In North Carolina, US 21 originally entered the state along today's NC 51 into Pineville, then followed Old Pineville Road into Charlotte. In the mid-1930s, US 21 moved over to South Boulevard from Old Pineville Road. In 1969, US 21 was rerouted following today's I-77 alignment, the old route was replaced by an extension of US 521. From 1975–1987, US 21 moved north in segments onto I-77 to its current alignment ending at exit 16A (Sunset Road). Further north, US 21 originally followed Old Statesville Road, replaced in 1956 by NC 115. In 1966, US 21 was bypassed around Jonesville and Elkin, replaced with US 21 Bus.^{[4][unreliable source]}

US 21 in Beaufort, South Carolina, was rerouted around the city over former SC 280 as well as a portion of SC 802. The new routing went into effect on February 26, 2012.^[5]

Browse numbered routes
← US 20A	OH	→ SR 21

State	County	Location	mi[6][7][8]	km	Exit	Destinations	Notes
South Carolina	Beaufort	Hunting Island State Park	0.00	0.00		Sea Island Parkway / Campground Road	Southern terminus; road continues as Sea Island Parkway
		Lady's Island	14.50	23.34		US 21 Bus. north (Sea Island Parkway west) / SC 802 east (Sams Point Road)	Southern terminus of US 21 Bus.; western terminus of SC 802
		Port Royal	17.35	27.92		SC 281 north (Ribaut Road north)	Southern terminus of SC 281
			19.87	31.98		Parris Island M.C.R.D.	Interchange
			21.10	33.96		SC 128 west (Savannah Highway) – Bluffton, Hardeeville, Hilton Head Island	Eastern terminus of SC 128
		Beaufort	24.24	39.01		SC 170 (Robert Smalls Parkway) – Beaufort
		Burton	25.44	40.94		US 21 Bus. south – Beaufort	Northern terminus of US 21 Bus.
			26.86	43.23		SC 116 west – Laurel Bay	Eastern terminus of SC 116
		Gardens Corner	37.40	60.19		US 17 north – Charleston	Interchange; eastern end of US 17 concurrency
		Pocotaligo	44.00	70.81		US 17 Alt. begins / US 17 south to I-95 – Ridgeland, Savannah	Western end of US 17 concurrency; southern end of US 17 Alt. concurrency; southern terminus of US 17 Alt.
	Hampton	Yemassee	47.77	76.88		SC 68 west (Connely Street) / Flowers Street south (US 17 Conn. south) to I-95 – Hampton, Allendale	Eastern terminus of SC 68; northern terminus of US 17 Conn.
	Colleton	​	49.39	79.49		US 17 Alt. north (Hendersonville Highway) – Walterboro	Northern end of US 17 Alt. concurrency
		​	52.04	83.75		I-95 – Florence, Savannah	I-95 exit 42
		​	62.00	99.78		SC 63 (Sniders Highway) – Varnville, Walterboro
		Bells Crossroads	68.41	110.10		SC 64 (Bells Highway) – Ehrhardt, Walterboro
		Smoaks	77.10	124.08		SC 217 (Lodge Highway) – Lodge
	Bamberg	Whetstone Crossroads	83.20	133.90		SC 61 (Edisto River Road) – Bamberg
	Orangeburg	Branchville	88.65	142.67		US 78 west (Edward Street) – Bamberg	Southern end of US 78 concurrency
			88.85	142.99		US 78 east (Dorange Road) – Charleston	Northern end of US 78 concurrency
			89.26	143.65		SC 210 north – Bowman	Southern terminus of SC 210
		Orangeburg	104.16	167.63		US 21 Bus. north (Rowesville Road) / Stonewall Jackson Boulevard (US 601 Truck north / SC 4 west)	Southern end of US 601 Truck concurrency; southern terminus of US 21 Bus.; eastern terminus of SC 4
			104.23	167.74		US 178 east (Charleston Highway east) / US 178 Bus. west (Charleston Highway west) – Charleston	Southern end of US 178 concurrency; eastern terminus of US 178 Bus.
			105.55	169.87		US 301 (Five Chop Road) – Santee, Bamberg
			105.65	170.03		SC 33 (Russel Street) – Cameron
			107.50	173.00		US 601 (Magnolia Street) / US 601 Truck ends – St. Matthews, Bamberg	Northern end of US 601 Truck concurrency; northern terminus of US 601 Truck
			108.59	174.76		US 178 west (Chestnut Street) / Columbia Road south (US 21 Conn. south) – North	Northern end of US 178 concurrency; northern terminus of US 21 Conn.; US 21 turns right off of Chestnut Street and onto Columbia Road.
	Calhoun	​	120.48	193.89		SC 172 – North
		​	120.58	194.05		SC 6 east to I-26	Southern end of SC 6 concurrency
		​	122.15	196.58		SC 6 north (Center Hill Road) – Swansea	Northern end of SC 6 concurrency
	Lexington	​	127.48	205.16		I-26 – Columbia, Charleston	I-26 exit 129
	Calhoun	Sandy Run	130.23	209.58		US 176 east (Old State Road) – St. Matthews	Southern end of US 176 concurrency
	Lexington	​	137.13	220.69		I-26 – Columbia, Charleston	I-26 exit 119
		​	138.98	223.67		US 321 south – Gaston, Swansea	Southern end of US 321 concurrency
		Cayce	141.48	227.69		I-77 north – Charlotte	I-77 exit 1
			141.87	228.32		I-26 – Charleston, Spartanburg	I-26 exit 115
			142.97	230.09		SC 2 north (Frink Road)	Southern terminus of SC 2
		West Columbia	144.45	232.47		SC 302 south (Airport Boulevard) – Aiken, Columbia Airport	Northern terminus of SC 302
		Cayce	146.23	235.33		SC 2 (State Street)
	Richland	Columbia	147.22	236.93		SC 48 Truck east (Blossom Street / US 21 Conn. east / US 76 Conn. east) to US 76 east / US 378 east	Western terminus of US 21 Conn., US 76 Conn., and SC 48 Truck; US 21, US 176, and US 321 turn left off of Blossom Street and onto Huger Street.
			147.86	237.96		US 1 / US 378 (Gervais Street) – South Carolina State Museum, Confederate Relic Room, EdVenture, Columbia SC Visitors Center, Convention Center, Colonial Life Arena
			148.16	238.44		SC 12 east (Hampton Street) – Fort Jackson	One-way couplet
			148.26	238.60		SC 12 west (Taylor Street) – Lexington
			148.76	239.41		I-126 west / US 76 west to I-20 – Greenville, Spartanburg	Southern end of I-126/US 76 concurrency; Rep. T. Moffatt Burriss Sr. Interchange
			149.08	239.92		I-126 ends	Northern end of I-126 concurrency
			149.38	240.40		SC 48 east (Assembly Street) – Columbia Museum of Art	Western terminus of SC 48
			149.46	240.53		US 76 east (Elmwood Avenue)	Northern end of US 76 concurrency
			149.97	241.35		US 176 west (River Drive)	Northern end of US 176 concurrency
			150.66	242.46		SC 16 (Sunset Drive)
			151.23	243.38		SC 215 north (Monticello Road)	Southern terminus of SC 215
			152.22	244.97		US 321 north (Fairfield Street) – Winnsboro	Northern end of US 321 concurrency
			154.76	249.06		I-20 – Florence, Augusta	I-20 exit 71
		Blythewood	162.17	260.99		I-77 – Columbia, Charlotte	I-77 exit 24
			163.46	263.06		SC 555 (Farrow Road) – Columbia
	Fairfield	​	171.40	275.84		Coleman Highway west (US 21 Conn. north) – Winnsboro	Southern terminus of US 21 Conn.; eastern terminus of Coleman Highway
		Ridgeway	172.09	276.95		SC 34 east (Palmer Street) – Lugoff, Camden	Southern end of SC 34 concurrency
			172.31	277.31		SC 34 west (Church Street) – Winnsboro Mills	Northern end of SC 34 concurrency
		​	189.11	304.34		SC 200 – Winnsboro	Southern end of SC 200 concurrency
	Chester	Great Falls	192.07	309.11		SC 99 north (Chester Avenue) – Richburg	Southern terminus of SC 99
			193.29	311.07		SC 97 north – Chester	Southern end of SC 97 concurrency
			193.43	311.30		SC 97 south / SC 200 north – Lancaster	Northern end of SC 97 and SC 200 concurrencies
		Fort Lawn	200.93	323.37		SC 9 (Chester Avenue) – Richburg, Lancaster
		​	206.23	331.90		SC 223 (Wylies Mill Road) – Richburg
	York	​	213.55	343.68		SC 5 south – Lancaster	Interchange; southern end of SC 5 concurrency; to Andrew Jackson State Park
		Lesslie	215.67	347.09		Lesslie	Interchange via connector road
Rock Hill		217.26	349.65	Lesslie, Red River	Interchange
		218.02	350.87	I-77 – Columbia, Charlotte	I-77 exit 77
		218.72	352.00	SC 5 / SC 121 (Main Street)	Access to Piedmont Medical Center; northern end of SC 5 concurrency; southern end of SC 121 concurrency
		220.20	354.38	SC 122 (Dave Lyle Boulevard) to I-77	Interchange
		222.36	357.85	SC 322 west (Cherry Road west) / SC 121 ends	Northern end of SC 121 concurrency; northern terminus of SC 121; eastern terminus of SC 322
		222.80	358.56	I-77 – Columbia, Charlotte	I-77 exit 82
		223.00	358.88	SC 161 north (Celanese Road) to I-77 north – Charlotte, York	Southern terminus of SC 161
Fort Mill		224.37	361.09	US 21 Bus. north (Spratt Street) – Fort Mill	Southern terminus of US 21 Bus.
		226.42	364.39	SC 160 – Tega Cay
		229.20	368.86	SC 460 (Springfield Parkway) – Tega Cay, Fort Mill
		230.35	370.71	US 21 Bus. south (Old Nation Road)	Northern terminus of US 21 Bus.
		231.14	371.98	SC 51 north (Pineville–Rock Hill Road) – Pineville	Southern terminus of SC 51 (northern segment)
		231.89	373.19	I-77 south – Columbia	Southern end of I-77 concurrency; I-77 exit 90
			232.52 0.00	374.20 0.00	South Carolina–North Carolina line
North Carolina	Mecklenburg	Charlotte	0.9	1.4	1A	Westinghouse Boulevard	Exit numbers follow I-77
			1.8	2.9	1B	I-485 – Huntersville, Pineville	Formerly exit 2 (southbound) before August 2010; I-485 exit 67
			2.8	4.5	3	Arrowood Road	Formerly exit 2 (northbound) before August 2010
			3.7	6.0	4	Nations Ford Road
			4.8	7.7	5	Tyvola Road	Single-point urban interchange
			6.0	9.7	6A	Woodlawn Road south (Charlotte Route 4 east) – Queens University	To Pfeiffer University
			6.2	10.0	6B	To NC 49 (S. Tryon Street) / Billy Graham Parkway (Charlotte Route 4 west)	To Billy Graham Library and Charlotte Douglas International Airport; southbound signed as NC 49 south (S. Tryon St. south) only
			7.3	11.7	7	To NC 49 / Clanton Road
			8.3	13.4	8	To NC 160 / Remount Road	Northbound exit and southbound entrance
			9.0	14.5	9A	NC 160 (West Boulevard)	Southbound exit and northbound entrance; access from collector-distributor lanes
			9.4	15.1	9B	I-277 north / US 74 east (John Belk Freeway)	Access from collector-distributor lanes; I-277 exits 1B-C
			9.5	15.3	9C	US 74 west (Wilkinson Boulevard) to US 29 / NC 27	US 29 and NC 27 signed northbound only; access from collector-distributor lanes; US 74 exits 1B-C
			9.9	15.9	10A	US 29 / NC 27 (Morehead Street)	Southbound exit and northbound entrance
			10.4	16.7	10	Trade Street / Fifth Street	Signed southbound as exits 10B (Trade Street east) and 10C (Fifth Street/Trade Street west)
			11.0	17.7	11A	I-277 south / NC 16 south (Brookshire Freeway east) – Downtown Charlotte	I-277 exits 5A-B
			11.2	18.0	11B	NC 16 north (Brookshire Freeway west)	Left exit northbound; NC 16 exits 5A-B
					—	I-77 north (Express lanes)	Southern terminus of HOV3+/toll lanes
					—	I-277 south	Express lanes only, southbound exit and northbound entrance
			12.4	20.0	12	Lasalle Street / Atando Avenue
			13.3	21.4	13	I-85 – Greensboro, Spartanburg	Signed as exits 13A (north) and 13B (south); hybrid interchange; I-85 exit 38
					—	I-85 north	Express lanes only; northbound exit and southbound entrance
			15.8	25.4		I-77 north – Statesville	Northern end of I-77 concurrency; I-77 exit 16
			16.3	26.2		NC 115 north (Old Statesville Road)	Southern terminus of NC 115
			18.9	30.4		NC 24 (W.T. Harris Boulevard)	To Northlake Mall
		Huntersville				Alexandriana Road to I-485
			25.7	41.4		NC 73 (Sam Furr Road) – Concord
		Cornelius	28.8	46.3		I-77 south – Charlotte	Southern end of I-77 concurrency; I-77 exit 28
		Davidson	30.2	48.6	30	Griffith Street – Davidson	Exit numbers follow I-77
	Lake Norman				Lake Norman Causeway
	Iredell	Mooresville	32.1	51.7	31	Langtree Road
			33.7	54.2		I-77 north – Statesville	Northern end of I-77 concurrency; I-77 exit 33
			36.4	58.6		NC 150 (Plaza Drive)	Interchange
			39.1	62.9		NC 115 south (Statesville Highway)	Southern end of NC 115 concurrency
		​	43.3	69.7		I-77 – Charlotte, Statesville	I-77 exit 42
		Statesville	51.2	82.4		US 70 (Garner Bagnal Boulevard) – Conover, Salisbury
			51.9	83.5		US 64 west (Front Street) / NC 115 north (Center Street)	Northern end of NC 115 concurrency; southern end of US 64 concurrency
			52.3	84.2		NC 90 west (Water Street)	Eastern terminus of NC 90
			53.2	85.6		US 64 east (Davie Avenue) – Mocksville	Northern end of US 64 concurrency
			54.1	87.1		I-40 – Hickory, Winston-Salem	I-40 exit 151
		​	57.2	92.1		I-77 – Statesville, Elkin	I-77 exit 54
		Harmony	66.9	107.7		NC 901 (Memorial Highway) – Union Grove
	Yadkin	Brooks Crossroads	79.2	127.5		US 421 – Wilkesboro, Yadkinville, Winston-Salem
		​	85.4	137.4		I-77 south / US 21 Bus. north – Statesville, Jonesville	Southern end of I-77 concurrency; I-77 exit 79; southern terminus of US 21 Bus.
		Jonesville	88.5	142.4	82	NC 67 – Jonesville, Boonville, Elkin	Exit number follows I-77
	Yadkin River				Sgt. Gregory Keith Martin Memorial Bridges
	Surry	Elkin	90.3	145.3		I-77 north – Wytheville	Northern end of I-77 concurrency; southbound exit and northbound entrance; I-77 exit 83
			91.3	146.9		NC 268 Byp. to I-77 north – Elkin	Interchange; to Elkin Municipal Airport; I-77 exit 85
			92.8	149.3		US 21 Bus. south – Elkin	Northern terminus of US 21 Bus.
	Wilkes	No major junctions
	Alleghany	​	111.2	179.0		Blue Ridge Parkway	Interchange via connector roads
		Sparta	118.2	190.2		NC 18 (Whitehead Street) – Laurel Springs
		Twin Oaks	121.1	194.9		US 221 south – Jefferson	Southern end of US 221 concurrency
			124.3 0.00	200.0 0.00		North Carolina–Virginia line
Virginia	Grayson	Independence	3.86	6.21		US 221 north / US 58 (Main Street) – Mouth of Wilson, Galax	Northern end of US 221 concurrency
		Elk Creek	14.77	23.77		SR 658 (Comers Rock Road) – Comers Rock
		​	15.67	25.22		SR 805 (Spring Valley Road) to SR 94 – Fries
	Wythe	Speedwell	21.26	34.21		SR 619 (Saint Peters Road) / SR 749 (Cedar Springs Road) – Cedar Springs, Rural Retreat
		​	26.03	41.89		SR 690 (Crockett Road, Cripple Creek Road) – Crockett, Cripple Creek
		​	31.13	50.10		SR 696 (Barrett Mill Road) – Big Survey Wildlife Management Area
		Wytheville	33.63	54.12		US 11 south (Lee Highway)	Southern end of US 11 concurrency
			33.94	54.62		US 11 north (Main Street)	Northern end of US 11 concurrency
			34.99	56.31		I-81 / US 52 to I-77 – Bristol, Roanoke	Northern terminus; I-81 exit 70; road continues west as US 52 (4th Street north)
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       HOV only       Incomplete access

There are currently four business loops, four connectors, and one truck route along its route.

• U.S. Route 21 Business (Beaufort, South Carolina)
• U.S. Route 21 Business (Orangeburg, South Carolina)
• U.S. Route 21 Connector (Orangeburg, South Carolina)
• U.S. Route 21 Connector (West Columbia, South Carolina)
• U.S. Route 21 Connector (Columbia, South Carolina)
• U.S. Route 21 Connector (Ridgeway, South Carolina)
• U.S. Route 21 Business (Fort Mill, South Carolina)
• U.S. Route 21 Business (Elkin, North Carolina)
• U.S. Route 21 Truck (Sparta, North Carolina)

Auxiliary routes of US 21:

• U.S. Route 121
• U.S. Route 221
• U.S. Route 321
• U.S. Route 421
• U.S. Route 521

• Media related to U.S. Route 21 at Wikimedia Commons
• Endpoints of U.S. Highway 21