Judith Marjorie Collins (born May 1, 1939) is an American singer-songwriter and musician with a career spanning seven decades. An Academy Award-nominated documentary director and a Grammy Award-winning recording artist, she is known for her eclectic tastes in the material she records (which has included folk music, country, show tunes, pop music, rock and roll and standards), for her social activism, and for the clarity of her voice. Her discography consists of 36 studio albums, nine live albums, numerous compilation albums, four holiday albums, and 21 singles.

Collins' debut studio album, A Maid of Constant Sorrow, was released in 1961 and consisted of traditional folk songs. She had her first charting single with "Hard Lovin' Loser" (No. 97) from her fifth studio album In My Life (1966), but it was the lead single from her sixth studio album Wildflowers (1967), "Both Sides, Now" – written by Joni Mitchell – that gave her international prominence. The single reached No. 8 on the Billboard Pop Singles chart and won Collins her first Grammy Award for Best Folk Performance. She enjoyed further success with her recordings of "Someday Soon", "Chelsea Morning" (also written by Mitchell), "Amazing Grace", "Turn! Turn! Turn!", and "Cook with Honey".

Collins experienced the biggest success of her career with her recording of Stephen Sondheim's "Send in the Clowns" from her tenth studio album Judith (1975). The single peaked at No. 36 on the Billboard Pop Singles chart in 1975 and then again in 1977 at No. 19, spending 27 non-consecutive weeks on the chart and earning her a Grammy Award nomination for Best Pop Vocal Performance, Female, as well as a Grammy Award for Sondheim for Song of the Year. Judith also became her best-selling studio album; it was certified Gold by the RIAA in 1975 for sales of over 500,000 copies and Platinum in 1996 for sales of over 1,000,000 copies.

In 2017, Collins's rendition of the song "Amazing Grace" was selected for preservation in the National Recording Registry by the Library of Congress as being "culturally, historically, or aesthetically significant". That same year, she received a Grammy Award nomination for Best Folk Album for Silver Skies Blue with Ari Hest. In 2019 at the age of 80, she scored her first No. 1 album on an American Billboard chart with Winter Stories, a duet album with Norwegian singer, songwriter, and guitarist Jonas Fjeld featuring Chatham County Line. In 2022, she released her first studio album of all original material, titled Spellbound, and it earned her another Grammy nomination for Best Folk Album.