"Weak" is a song by American R&B vocal trio SWV from their debut studio album, It's About Time (1992). It was written and produced by Brian Alexander Morgan, who composed the lyrics based on a young person falling in love for the first time. Inspired by his crush on singer Chanté Moore, Morgan originally wrote the song for Charlie Wilson, but he later decided to give the song to SWV. Morgan later revealed that lead singer of SWV, Coko, did not like the song and gave him attitude during the recording of the single. Coko, in turn, said that she did not like the song because she found it difficult to sing initially because the song forced her to do things she was not used to.
A partially re-recorded version of "Weak" was released in April 1993 by RCA Records as the third single from the album. It topped the US Billboard Hot 100 for two weeks in July 1993, as well as the Cash Box Top 100, and sold over one million copies domestically and was awarded a platinum certification from the Recording Industry Association of America (RIAA). It also topped the Billboard Hot R&B Singles chart for two weeks. Outside the US, the single reached number six on the New Zealand Singles Charts and number 33 on the UK Singles Chart. Billboard ranked the song at number 72 on their list of the "100 Greatest Girl Group Songs of All Time".
Sheet music for the song "Weak" shows the key of D minor with a tempo of "slow groove" at 63 beats per minute.
Pan-European magazine Music & Media described "Weak" as a "lush ballad".
"Weak" was included in Pitchfork's "53 Best R&B Songs of the '90s". In 2026, American girl group Girlset sampled the song in their single "Tweak".