Katharine Juliet Ross was born on January 29, 1940, in Los Angeles, California, to Katharine Elizabeth Washburn and Dudley Tyng Ross. Her father was a lieutenant in the Navy, and the family moved around quite a bit before settling in Walnut Creek, California.

Katharine Ross attended Las Lomas High School and later studied at Santa Rosa Junior College and Diablo Valley College. She began her acting career in the early 1960s, making her television debut in 1962 and her film debut in the Civil War-themed drama "Shenandoah" in 1965.

Her breakthrough came with her role as Elaine Robinson in the 1967 film "The Graduate," for which she received an Academy Award nomination for Best Supporting Actress, a BAFTA nomination, and a Golden Globe Award for New Star of the Year.

She continued her success with roles in two 1969 westerns, "Butch Cassidy and the Sundance Kid" and "Tell Them Willie Boy Is Here," both of which earned her BAFTA Awards for Best Actress.

In the 1970s, she starred in the horror film "The Stepford Wives," winning the Saturn Award for Best Actress, and the drama "Voyage of the Damned," for which she won her second Golden Globe Award.

She also appeared in several TV movies and series during this time, including "The Colbys" from 1985 to 1987. She took a step back from acting in the 1990s but returned with a supporting role in the cult film "Donnie Darko" in 2001.

She continued to work in film and television, including providing a voice role for the animated series "American Dad!" in 2016 and starring in the comedy-drama "The Hero" in 2017 alongside her husband, Sam Elliott.

Katharine Ross has been married five times, with her current husband being actor Sam Elliott since 1984. They have one daughter, Cleo Rose Elliott. Ross has also authored several children's books, including "The Fuzzytail Friends Great Egg Hunt" and "Grover, Grover, Come on Over!"

Her net worth is estimated to be around $5 million, reflecting her successful career in the entertainment industry.