Sigrid Madeline Thornton (born 12 February 1959) is an Australian film and television actress. Her television work includes Prisoner (1979–80), All the Rivers Run (1983), SeaChange (1998–2019) and Wentworth (2016–2018). She also starred in the American Western series Paradise (1988–91). Her film appearances include Snapshot (1979), The Man from Snowy River (1982), Street Hero (1984) and Face to Face (2011). She won the AACTA Award for Best Guest or Supporting Actress in a Television Drama for the 2015 miniseries Peter Allen: Not the Boy Next Door.