Katharine Houghton Hepburn (May 12, 1907 – June 29, 2003) was an American actress. Known for her fierce independence and spirited personality, Hepburn was a leading lady in Hollywood for more than 60 years. She appeared in a range of genres, from screwball comedy to literary drama, and she received four Academy Awards -- a record for any performer -- for Best Actress. In 1999, Hepburn was named by the American Film Institute as the greatest female star of Classic Hollywood Cinema.

Raised in Connecticut by wealthy, progressive parents, Hepburn began to act while studying at Bryn Mawr College. After four years in the theatre, favorable reviews of her work on Broadway brought her to the attention of Hollywood. Her early years in the film industry were marked with success, including an Academy Award for her third picture, Morning Glory (1933), but this was followed by a series of commercial failures that led her to be labeled "box office poison" in 1938. Hepburn masterminded her own comeback, buying out her contract with RKO Radio Pictures and acquiring the film rights to The Philadelphia Story, which she sold on the condition that she be the star. In the 1940s, she was contracted to Metro-Goldwyn-Mayer, where her career focused on an alliance with Spencer Tracy. The screen partnership spanned 25 years and produced nine movies.

Hepburn challenged herself in the latter half of her life, as she regularly appeared in Shakespearean stage productions and tackled a range of literary roles. She found a niche playing middle-aged spinsters, such as in The African Queen (1951), a persona the public embraced. Three more Oscars came for her work in Guess Who's Coming to Dinner (1967), The Lion in Winter (1968), and On Golden Pond (1981). In the 1970s, she began appearing in television films, which became the focus of her career in later life. She remained active into old age, making her final screen appearance in 1994 at the age of 87. After a period of inactivity and ill health, Hepburn died in 2003 at the age of 96.

Hepburn famously shunned the Hollywood publicity machine and refused to conform to society's expectations of women. She was outspoken, assertive, athletic, and wore trousers before it was fashionable for women to do so. She was briefly married as a young woman, but thereafter lived independently. A 26-year affair with her co-star Spencer Tracy was hidden from the public. With her unconventional lifestyle and the independent characters she brought to the screen, Hepburn epitomized the "modern woman" in the 20th-century United States and is remembered as an important cultural figure.