The family-owned company that makes the tiny, intense-flavored candies owes a lot to the former president.
Reagan's love for the candy "made us a worldwide company overnight," said chairman Herman Rowland.
It all began in 1967, when the San Francisco Bay-area company started supplying Reagan, then serving his first term as California's governor, with miniature jelly beans to help him quit smoking.
"It's gotten to the point where we can hardly start a meeting or make a decision without passing around the jar of jelly beans," Reagan wrote to Rowland in 1973.
Reagan carried the tradition to the White House, where the company's jelly beans became a must-have at Cabinet meetings.
The president, whose favorite flavor was licorice, ordered 7,000 pounds of Jelly Bellys for his 1981 inauguration, and Rowland traveled to Washington to help design a special jelly bean jar bearing the presidential seal.
The company produces about 13 billion individual jelly beans a year, up from 4 billion in 1984. It has 670 employees, compared with around 50 in the 1960s.
Mourners have been leaving jelly beans in Reagan's memory at his presidential library and other spots.
About 500,000 visitors a year tour the factory in Fairfield, posing for pictures in front of the Reagan portraits that have had a place of honor at Jelly Belly for years.
One shows him in front of the American flag, depicted in cherry, coconut and blueberry jelly beans. Another is a swirl of strawberry daiquiri, bubble gum and other flavors that depicts him with wife Nancy.
Patricia Kriletich, 54, of Novato, recalled the first time she heard about Jelly Bellys, during Reagan's presidency.
"I used to say, `What's a Jelly Belly?' He took a little company and made it famous," she said during a tour of the factory this week. "They have a lot to thank him for."