98 (ninety-eight) is the natural number following 97 and preceding 99.

98 is:

• a Wedderburn–Etherington number^[1]
• a nontotient
• a number of non-isomorphic set-systems of weight 7

• 98 Ianthe, a main-belt asteroid
• Messier 98, a magnitude 11.0 spiral galaxy in the constellation Coma Berenices.
• The New General Catalogue object NGC 98, a magnitude 12.7 spiral galaxy in the constellation Phoenix.

• Windows 98, a Microsoft operating system for personal computers
• Microsoft Flight Simulator 98, a flight simulator program

• MPTA-098, the Main Propulsion Test Article built as a systems testbed for the Space Shuttle program
• Pathfinder (OV-098), a Space Shuttle simulator built by NASA in 1977
• STS-98, Space Shuttle Atlantis mission launched February 7, 2001

Ninety-eight is:

• The atomic number of californium, an actinide
• +98, the code for international direct dial phone calls to Iran
• 98 Degrees, an American adult contemporary boy band
• 98.6 degrees Fahrenheit is normal body temperature
• "98.6", a 1967 hit song by Keith
• 10-98 code in police code means "Assignment Completed"
• The number of sons of Ater in the census of men of Israel upon return from exile (Bible, Ezra 2:16)
• Beach 98th Street, often referred as Beach 98th Street–Playland, a station on the New York City Subway's IND Rockaway Line
• Expo '98, a World's Fair held in Lisbon, Portugal, from May to September 1998
• Oldsmobile 98, a full-size automobile and the highest-end of the Oldsmobile division of General Motors
• Power 98 (radio station), an English radio station of So Drama! Entertainment in Singapore
• Power 98 (film), a 1996 film starring Eric Roberts about a Los Angeles talk radio station.
• "Power 98", official nickname of radio station WPEG, in Charlotte, North Carolina
• Saab 98, a project by automaker Saab for a combi coupé based on the Saab 95
• Spirit of '98, a ship owned by Cruise West built to accommodate 98 passengers
• The Trail of '98, a 1928 western film

• The highest jersey number allowed in the National Hockey League, as 99 was retired by the entire league to honor Wayne Gretzky and major-league sports only allow one- or two-digit uniform numbers.

• List of highways numbered 98