"1 Thing" is a song written by American R&B singer-songwriter Amerie and Rich Harrison for Amerie's second studio album, ''Touch'' (2005). The song is influenced by go-go rhythms and features a prominent sample of The Meters' 1970 funk recording of "Oh, Calcutta!", written by Stanley Walden. Its lyrics focus on an unidentified "thing" that fuels a romantic attraction.
The song was released as ''Touch'' lead single in 2005, and is the only single from the soundtrack to the 2005 romantic comedy film ''Hitch''. "1 Thing" peaked at number eight in the United States and number four in the United Kingdom, becoming Amerie's first top ten single and her biggest hit to date, also peaking at number one on the U.S. R&B singles chart. Its digital download and ringtone releases were each certified gold by the Recording Industry Association of America. The song earned Amerie a Grammy Award nomination for Best Female R&B Vocal Performance at the 2006 Grammy Awards. A remix of "1 Thing" features rapper Eve. The song ranked at number twenty-two on Rolling Stone's "100 Best Songs of the 2000s Decade" list.