Janet Seidel (born 28 May 1955) is an Australian jazz vocalist and pianist.
Her albums, recorded with musicians including her brother, bassist David Seidel, have been nominated for prizes such as the ARIA Music Awards. Her album Moon of Manakoora won the Bell Award for Best Australian Jazz Vocal Album in 2006. Thanks to an episode of Glee where Janet's version of "A Man and a Woman" was used, her CD Comme Ci, Comme Ça is now a best seller.
Seidel has been described as being a "virtual institution" in her country. She is currently a music teacher at Sydney Girls High School.