Walter Brennan (July 25, 1894 – September 21, 1974) was an American actor. Highly regarded as a film character actor, Brennan won the Academy Award for Best Supporting Actor three times.

Born in Lynn, Massachusetts less than two miles from his family's home in Swampscott, to Irish emigrants, he was christened Walter Andrew Brennan. His father was an engineer and inventor. Walter Brennan studied engineering at Rindge Technical High School in Cambridge, Massachusetts.

While in school, Brennan became interested in acting, and began to perform in vaudeville. While working as a bank clerk, he enlisted in the U.S. Army and served as a private with the 101st Field Artillery Regiment in France during World War I. Following the war, he moved to Guatemala and raised pineapples, before settling in Los Angeles. During the 1920s, he became involved in the real estate market, where he made a fortune. Unfortunately, he lost most of his money when the market took a sudden downturn.