Sheriff’s deputies located Lee in Pico Rivera just after 9 p.m. Tuesday.
The 92-year-old, who suffers from dementia and heart problems, had been missing since Monday.
According to his wife, Lee left his home in Huntington Beach at 1 p.m. for his regular swim at Los Caballeros Sports Club in Fountain Valley. But he never came home.
Lee was last seen driving a tan 2011 Mercedes 300 with California license plate “2GOLDS.”
Police said he purchased gas around 8:30 a.m. Tuesday in the Mojave area.
His card was later used at a Best Buy in Westminster and then a gas station in Studio City.
Lee’s wife and children were worried sick, but he said didn’t understand what the big deal was.
“I didn’t know I was missing,” he joked after he was found on Tuesday night.
“You know he’s gonna be 93 this year, so obviously it’s a big wake-up call,” said son Sammy Lee II.
“We haven’t had an incident to this magnitude. I’m sure everyone out there with parents who are at that age — there comes a time. And obviously, this is our time.”
Lee won a gold medal in the men’s platform at the London Games in 1948, becoming the first American of Asian descent to win a gold medal.
At 32, he won again at Helsinki in 1952, becoming the oldest diver to win a gold medal.
Lee has also coached other Olympic greats, such as Bob Webster and silver-medalist Greg Louganis.