Mary Louise Streep (born June 22, 1949) is an American actress. Often described as "the best actress of her generation", Streep is particularly known for her versatility and accent adaptability. She has received numerous accolades throughout her career spanning over four decades, including a record 21 Academy Award nominations, winning three, and a record 32 Golden Globe Award nominations, winning eight.

Streep made her stage debut in 1975 Trelawny of the Wells and received a Tony Award nomination the following year for a double-bill production of 27 Wagons Full of Cotton and A Memory of Two Mondays. In 1977, she made her film debut in Julia. In 1978, she won her first Primetime Emmy Award for a leading role in the mini-series Holocaust, and received her first Oscar nomination for The Deer Hunter. She won the Academy Award for Best Supporting Actress for playing a troubled wife in Kramer vs. Kramer (1979) and went on to establish herself as a film actor in the 1980s. She won the Academy Award for Best Actress for starring as a Holocaust survivor in Sophie's Choice (1982) and had her biggest commercial success to that point in Out of Africa (1985). She continued to gain awards, and critical praise, for her work in the late 1980s and 1990s, but commercial success was varied, with the comedy Death Becomes Her (1992) and the drama The Bridges of Madison County (1995), her biggest earners in that period.

Streep reclaimed her stardom in the 2000s and 2010s with starring roles in Adaptation (2002), The Hours (2002), The Devil Wears Prada (2006), Doubt (2008), Mamma Mia! (2008), Julie & Julia (2009), It's Complicated (2009), Into the Woods (2014), The Post (2017) and Little Women (2019). She also won her third Academy Award for her portrayal of British Prime Minister Margaret Thatcher in The Iron Lady (2011). Her stage roles include The Public Theater's 2001 revival of The Seagull, and her television roles include two projects for HBO, the miniseries Angels in America (2003), for which she won another Primetime Emmy Award, and the drama series Big Little Lies (2019).

Streep has been the recipient of many honorary awards. She was awarded the AFI Life Achievement Award in 2004, Gala Tribute from the Film Society of Lincoln Center in 2008, and Kennedy Center Honor in 2011 for her contribution to American culture, through performing arts. President Barack Obama awarded her the National Medal of Arts in 2010, and the Presidential Medal of Freedom in 2014. In 2003, the French government made her a Commander of the Order of Arts and Letters. She was awarded the Golden Globe Cecil B. DeMille Award in 2017.