Mary Louise "Meryl" Streep (born June 22, 1949) is an American actress. Known for her versatility and adept accent work, she has been described as "the best actress of her generation". She has received numerous accolades throughout her career spanning over five decades, including three Academy Awards, two British Academy Film Awards, eight Golden Globe Awards, four Emmy Awards, and two Screen Actors Guild Awards, in addition to nominations for seven Grammy Awards and a Tony Award.

Streep made her feature film debut in Julia (1977) and soon established herself as one of the most respected actresses of all time. She has received three Academy Awards, the first for Best Supporting Actress for playing a troubled wife in Kramer vs. Kramer (1979), followed by two Best Actress wins for playing a Holocaust survivor in Sophie's Choice (1982) and Margaret Thatcher in The Iron Lady (2011). Throughout her career she has continued to earn critical acclaim for her diverse roles on film ranging from the dramatic in The Deer Hunter (1978), Silkwood (1983), Out of Africa (1985), The Bridges of Madison County (1995), Doubt (2008), August: Osage County (2013), Into the Woods (2014), and The Post (2017) to the comedic in The Devil Wears Prada (2006), Mamma Mia! (2008), Julie & Julia, It's Complicated (both 2009), and Florence Foster Jenkins (2016). She was also featured in Woody Allen's comedy-drama Manhattan (1979).

On stage, Streep made her debut in 1975 in Trelawny of the Wells, and the following year she received a nomination for the Tony Award for Best Featured Actress in a Play for a double-bill production of 27 Wagons Full of Cotton and A Memory of Two Mondays. For her work on television, Streep has won four Emmy Awards, including Primetime Emmys for her acting roles in the miniseries Holocaust (1978) and Angels in America (2003). She has also taken roles in the HBO drama series Big Little Lies (2019) and the Hulu comedy-mystery series Only Murders in the Building (2023–24).

Streep has been the recipient of many honorary awards, including an Honorary César in 2003, the AFI Life Achievement Award in 2004, a Gala Tribute from the Film Society of Lincoln Center in 2008, the Kennedy Center Honor in 2011, an Honorary Golden Bear in 2012, the Golden Globe Cecil B. DeMille Award in 2017, and the Honorary Palme d'Or in 2024. 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.

Mary Louise Streep was born on June 22, 1949, in Summit, New Jersey, to artist Mary Wilkinson Streep and pharmaceutical executive Harry William Streep Jr. She has two younger brothers, Harry William Streep III and Dana David Streep, both actors. Streep's mother, whom she has compared in both appearance and manner to Dame Judi Dench, strongly encouraged her daughter and instilled confidence in her from a very young age. Streep said, "She was a mentor because she said to me, 'Meryl, you're capable. You're so great.' She was saying, 'You can do whatever you put your mind to. If you're lazy, you're not going to get it done. But if you put your mind to it, you can do anything.' And I believed her." Although she was naturally more introverted than her mother, when she later needed an injection of confidence in adulthood, she would consult her mother at times for advice.

Streep was raised as a Presbyterian in Basking Ridge, New Jersey, and attended Cedar Hill Elementary School and the Oak Street School, which was a junior high school at that time. In her junior high debut, she starred as Louise Heller in the play The Family Upstairs. In 1963, the family moved to Bernardsville, New Jersey, where she attended Bernards High School. Author Karina Longworth described her as a "gawky kid with glasses and frizzy hair", yet noted that she liked to show off in front of the camera in family home movies from a young age. At age 12, Streep was selected to sing at a school recital, leading to her having opera lessons from Estelle Liebling. Despite her talent, she later remarked, "I was singing something I didn't feel and understand. That was an important lesson—not to do that. To find the thing that I could feel through." She quit after four years. Streep had many Catholic school friends, and regularly attended Mass. She was a high school cheerleader for the Bernards High School Mountaineers. She was also chosen as the homecoming queen her senior year.

Although Streep appeared in numerous school plays during her high school years, she was uninterested in serious theater until acting in the play Miss Julie at Vassar College in 1969, in which she gained attention across the campus. Vassar drama professor Clinton J. Atkinson noted, "I don't think anyone ever taught Meryl acting. She really taught herself." Streep demonstrated an early ability to mimic accents and to quickly memorize her lines. She earned her AB in drama cum laude in 1971, before applying for an MFA from the Yale School of Drama. At Yale, she supplemented her course fees by working as a waitress and typist, and appeared in over a dozen stage productions per year; at one point, she became overworked and developed ulcers, so she contemplated quitting acting and switching to study law. Streep played a variety of roles on stage, from Helena in A Midsummer Night's Dream to an 80-year-old woman in a wheelchair in a comedy written by then-unknown playwrights Christopher Durang and Albert Innaurato. She was a student of choreographer Carmen de Lavallade, whom she introduced at the 2017 Kennedy Center Honors. Another of her teachers was Robert Lewis, a co-founder of the Actors Studio. Streep disapproved of some of the acting exercises she was asked to do, remarking that one professor taught the emotional recall technique by delving into personal lives in a way she found "obnoxious". She earned her MFA in drama from Yale in 1975. She also enrolled as a visiting student at Dartmouth College in 1970, and received an honorary Doctor of Arts degree from the college in 1981.

One of Streep's first professional jobs in 1975 was at the Eugene O'Neill Theater Center's National Playwrights Conference, during which she acted in five plays over six weeks. She moved to New York City in 1975, and was cast by Joseph Papp in a production of Trelawny of the Wells at the Vivian Beaumont Theater, opposite Mandy Patinkin and John Lithgow. She went on to appear in five more roles in her first year in New York, including in Papp's New York Shakespeare Festival productions of Henry V, The Taming of the Shrew with Raul Julia, and Measure for Measure opposite Sam Waterston and John Cazale. She entered into a relationship with Cazale at this time, and resided with him until his death three years later. She starred in the musical Happy End on Broadway, and won an Obie for her performance in the off-Broadway play Alice at the Palace.