Mary 'Mare' Megan Winningham is an actress and songwriter who has appeared in nearly 100 TV shows and feature films. She began her career in 1976 as a singer, and starred in numerous and diverse film roles before hitting it big as one of the original Brat Pack in Joel Schumacher's St. Elmo's Fire (1985) with Emilio Estevez, Andrew McCarthy, Demi Moore, Judd Nelson, and Ally Sheedy.

Mare attended Chatsworth High School with Val Kilmer, James Rekart and Kevin Spacey, but she was bitten by the acting bug much earlier on. She had enjoyed drama and music since primary school, taking a particular interest in the guitar and drums.

Since St. Elmo's Fire (1985), Mare has played some outstanding roles in a number of big films. She starred in the Tom Hanks comedy Turner & Hooch (1989). She has also starred in two feature films with Kevin Costner, The War (1994) and the western Wyatt Earp (1994), the latter directed by Lawrence Kasdan and co-starring Gene Hackman. Mare won a Best Supporting Actress Oscar nomination for her role opposite Jennifer Jason Leigh in Georgia (1995).

Bad Day on the Block (1997) saw her starring opposite Charlie Sheen and she put in a superb performance in Brothers (2009), a war drama co-starring Tobey Maguire and Natalie Portman.

Her myriad TV roles include ER (1994), Grey's Anatomy (2005), and 24 (2001) with Kiefer Sutherland.