The Iron Lady is a 2011 biographical drama film based on the life and career of Margaret Thatcher, a British politician who was the longest-serving Prime Minister of the United Kingdom of the 20th century and the first woman to hold the office. The film was directed by Phyllida Lloyd and written by Abi Morgan. Thatcher is portrayed primarily by Meryl Streep, and, in her formative and early political years, by Alexandra Roach. Thatcher's husband, Denis Thatcher, is portrayed by Jim Broadbent and by Harry Lloyd as the younger Denis. Thatcher's longest-serving cabinet member and eventual deputy, Geoffrey Howe, is portrayed by Anthony Head.

Despite the film's mixed reception, Streep's performance was widely acclaimed. She received her 17th Oscar nomination for her portrayal and ultimately won the award for the third time—29 years after her second Oscar win. She also earned her third Golden Globe Award for Best Actress – Motion Picture Drama award (her eighth Golden Globe Award win overall) and her second BAFTA Award for Best Actress in a Leading Role. The film also won the Academy Award for Best Makeup and the BAFTA Award for Best Makeup and Hair.

The film was loosely based on John Campbell's biography The Iron Lady: Margaret Thatcher, from Grocer's Daughter to Prime Minister.