Helen Rachel Slater (born December 15, 1963) is an American actress and singer-songwriter. She is best known for her role as the title character in the 1984 film Supergirl. She returned to the 2015 TV series of the same title, this time as Supergirl's adoptive mother, Eliza Danvers.

In the intervening years, she starred in several films including The Legend of Billie Jean (1985), Ruthless People (1986), The Secret of My Success (1987), and City Slickers (1991). She additionally found work as an actress in television, and stage projects, including three guest appearances on the series Smallville (2007–2010).

In the 2000s, she recorded three albums, on which she sings her own compositions and plays the piano.