Janet McTeer (born 5 August 1961) is an English actress. In 1997, she won the Tony Award for Best Actress in a Play, the Olivier Award for Best Actress, and the Drama Desk Award for Outstanding Actress in a Play for her role as Nora in A Doll's House (1996–97). She also won a Golden Globe Award and was nominated for the Academy Award for Best Actress for her role as Mary Jo Walker in the 1999 film Tumbleweeds, and was nominated for the Academy Award for Best Supporting Actress for her role as Hubert Page in the 2011 film Albert Nobbs. She was made an OBE in the 2008 Queen's Birthday Honours.

McTeer made her professional stage debut in 1984, and was nominated for the 1986 Olivier Award for Best Newcomer for The Grace of Mary Traverse. Other theatre roles include Yelena in Uncle Vanya (London), Veronique in God of Carnage (London & New York) and the title role in Mary Stuart (London & New York), which won her a second Drama Desk Award in 2009. On television, she starred in the title role of Lynda La Plante's The Governor (1995–96), received an Emmy Award nomination for Into the Storm (2009) and a Golden Globe nomination for The White Queen (2013).

She also appeared opposite Glenn Close in the final season of the drama series Damages (2012). Her other film roles include Half Moon Street (1986), Hawks (1988), Wuthering Heights (1992), Carrington (1995), Velvet Goldmine (1998), Songcatcher (2000), The Intended (2002), As You Like It (2006), Tideland (2005), Cat Run (2011), Woman in Black (2012), Maleficent (2014), The Divergent Series (2015–16) and Me Before You (2016).