Janet Seidel (28 May 1955 – 7 August 2017) was an Australian jazz vocalist and pianist.

Seidel studied at the Elder Conservatorium at the University of Adelaide (BMusic, 1973–1976).

She worked as a high school music teacher in New South Wales at the Sydney Girls High School^[1] and as a professional musician as a pianist and singer. From 1976 to 1980, she was an active member of the Adelaide Feminist Theatre Group. For their first show, The Carolina Chisel Show (1976), she wrote the piano arrangements. For the musical melodrama The Redheads' Revenge (1978), she wrote and arranged all the songs, conducted and played in the orchestra and was also involved in the writing, production and direction of the show. For the revue Out of the Frying Pan (1980), she wrote five original songs, collaborated with Judy Szekeres on the musical arrangement, played in the orchestra and was involved with the choreography.^[2]

Seidel's 18 CD albums, recorded with musicians including her brother, bassist David Seidel,^[3] have been nominated for prizes such as the ARIA Music Awards.^[4] Her album Moon of Manakoora won the Bell Award for Best Australian Jazz Vocal Album in 2006.^[5]

Seidel died on 7 August 2017 from ovarian cancer in Sydney at the age of 62.^[6] Some newspapers mistakenly reported her death as 8 August.^[7] A posthumous CD of previously unreleased recordings was released in September 2018 in Japan. Entitled You Are There, it was produced by David Seidel.