Police responded to a call around 8 p.m. PDT and confirmed Garner's identity from family members, AP reported.
As The ENQUIRER reported previously, Garner had suffered a stroke in May 2008, just weeks after his 80th birthday.
Although he was adept at drama and action, Garner was best known for his low-key, wisecracking style, especially with his hit TV series, "Maverick" and "The Rockford Files."
When he received the Screen Actors Guild's lifetime achievement award in 2005, he quipped, "I'm not at all sure how I got here."
Garner was born James Scott Bumgarner (some references say Baumgarner) in Norman, Okla. His mother died when he was 5, and friends and relatives cared for him and his two brothers for a time while his father was to California.
At 16 he dropped out of school and joined the Army, receiving a Purple Heart after being wounded in Korea.
In 1957 the then fledgling ABC network, desperate to compete on ratings-rich Sunday night, scheduled "Maverick" against CBS's powerhouse "The Ed Sullivan Show" and NBC's "The Steve Allen Show." ''Maverick" clocked them both.
"Maverick," which co-starred Jack Kelly as brother Bart Maverick, made its debut on Sept. 22, 1957.
After escaping the TV series the non-conformist thesp mafe movie history staring with Audrey Hepburn and Shirley MacLaine in “The Children's Hour” , a lesbian drama from director William Wyler.
He starred with Kim Novak in "Boys Night Out," and then fully established his box-office appeal with the 1963 blockbuster war drama "The Great Escape" as The Scrounger.
Two comedies with Doris Day — "The Thrill of It All" and "Move Over Darling" proved his box office appeal to men and women alike.
Garner demonstrated his versatility in comedies ("The Art of Love," ''A Man Could Get Killed," ''Skin Game"), suspense ("36 Hours," ''They Only Kill Their Masters," ''Marlowe" with Bruce Lee), Westerns ("Duel at Diablo," ''Hour of the Gun," ''Support Your Local Gunfighter") and CINERAMA ("Grand Prix"). The racing pic gave Garner a life-long passion for racing.
In a series of Polaroid commercials with actress Mariette Hartley, their chemistry was so natural, many through the couple married in real-life.
In the 1980s and 1990s, when most stars his age were considered over the hill, Garner's career remained strong -- teamed again with Julie Andrews in the gender/bender classic "Victor/Victoria".
He played a supporting role as a marshal in the 1994 "Maverick," a big-screen return to the TV series with Mel Gibson in Garner's title role.
His only Oscar nomination came for the 1985 "Murphy's Romance," a comedy about a small-town love affair co-starring Sally Field.
His favorite film, though, was Blake Edwards’ cynical 1964 war drama "The Americanization of Emily," which co-starred Julie Andrews.
Returning once again to the small screen Jim's "The Rockford Files" (1974-80) proved a solid hit, bringing him an Emmy and a new generation of fans. He later sued to get a piece of the profoits from the hugely successful show.
"It's not something I wanted to achieve, being famous," Garner said in an interview. "I was just trying to make a living."