One Thing or The One Thing may refer to:

• The One Thing (album), a 1993 album by Michael Bolton
• One Thing, a 1989 album by Sylvia Juncosa

• "One Thing" (Alicia Keys song), 2012
• "One Thing" (Finger Eleven song), 2003
• "One Thing" (Gravity Kills song), 2002
• "One Thing" (One Direction song), 2012
• "1 Thing", a 2005 song by Amerie
• "The One Thing" (song), a 1982 song by INXS
• "The One Thing", a 2014 song by Shakira from the album Shakira
• "One Thing", a song by Beach House from their 2015 album Thank Your Lucky Stars
• "One Thing", a song by Soulsavers from their 2015 album Angels & Ghosts
• "One Thing", a song by Hellyeah from their 2007 album Hellyeah
• "One Thing", a song by Nothingface from their 1997 album Pacifier
• "1 Thing", a song by STAYC from their 2024 album Metamorphic
• The opening lyric of "In the End", a song by Linkin Park

• The One Thing (book), 2013 non-fiction self-help book

• All pages with titles containing one thing
• All pages with titles containing 1 thing
• 1 (disambiguation)
• One (disambiguation)
• Thing (disambiguation)
• The One (disambiguation)
• One More Thing (disambiguation)
• Just One Thing, BBC radio show
• Thing 1, a fictional character from Dr. Seuss' The Cat In The Hat