American character actor, best known for his portrayals of western sidekicks and lovable or irascible old codgers.

During his lifetime Brennan offered so many different versions of his early years that it is virtually impossible to separate fact from fancy. He may have left home at age 11, or perhaps he remained home until he graduated from high school. He may have trained to be an engineer like his father, but whether he attended college for this purpose is open to speculation. It is very likely that he worked as a lumberjack, ditchdigger, and bank messenger but less likely that he raised pineapples in Guatemala. While he undoubtedly served with the 101st Field Artillery in World War I, the assertion that he lost his teeth and acquired his grating high-pitched voice in a gas attack is probably apocryphal.

After the war he sold real estate in California until he was encouraged by a coworker to rechannel his flamboyant salesmanship into acting. He entered films in 1923 as an extra and a stuntman, earning $7.50 per day. His first important film assignment came in 1930, when he was prominently featured in Universal's lavish musical revue The King of Jazz. Thereafter, he played a variety of bit parts and featured roles, ranging from youthful Cockneys to elderly patriarchs. Whenever assigned one of these character parts, he would inquire of the director, “With or without?”; asked, “With or without what?” Brennan would remove his dentures and answer, “Teeth!”

Hired for a minor role as a cabbie in producer Sam Goldwyn (Goldwyn, Samuel)'s The Wedding Night (1935), Brennan so impressed Goldwyn with his characterization that the producer signed him to a long-term contract, which led to a larger assignment in Barbary Coast (1935), the first of the actor's seven collaborations with director Howard Hawks (Hawks, Howard). Brennan's breakthrough role was that of the Swedish lumberman Swan Bostrom in Goldwyn's Come and Get It (1936), which earned for him his first best supporting actor Academy Award. Two years later he won a second Academy Award for his portrayal of a grandfatherly horse farm owner in Kentucky, and in 1940 he earned an unprecedented third Oscar for his performance as Judge Roy Bean (Bean, Roy) in The Westerner. His other noteworthy film roles include Pastor Pile in Sergeant York (1941), garrulous “rummy” Eddie in To Have and Have Not (1944), coldblooded outlaw leader Old Man Clanton in My Darling Clementine (1946), and cantankerous cattlehand Groot Nadine in Red River (1948). While earning $5,000 per week by the end of the 1940s, he also owned a working 12,000-acre (5,360-hectare) Oregon cattle ranch.

Continuing to flourish into the 1950s with such films as Bad Day at Black Rock (1955) and Rio Bravo (1959), Brennan also became a television star when, in 1957, he was cast as mulish West Virginia farmer Amos McCoy on the weekly situation comedy The Real McCoys, which lasted six years and 224 episodes. He went on to star in two additional TV series, Tycoon (1964) and The Guns of Will Sonnett (1967–69). In his final years Brennan often raised the hackles of his younger coworkers with his ultraconservative views, but few could argue with his fundamental professional philosophy: “My advice to actors? Very simple. Do your acting, son, but don't get caught at it.”