Roddenberry died of leukemia Thursday morning at her home in Bel-Air, said Sean Rossall, a family spokesman.
At Roddenberry's side were family friends and her son, Eugene Roddenberry Jr.
Roddenberry was involved in the "Star Trek" universe for more than four decades.
She played the dark-haired Number One in the original pilot, but metamorphosed into the blond, mini-skirted Nurse Christine Chapel in the original 1966-69 show.
She had smaller roles in all five of its television successors and many of the "Star Trek" movie incarnations, although she had little actual involvement in the productions.
She frequently was the voice of the ship's computer, and about two weeks ago she completed the same role for the upcoming J.J. Abrams movie "Star Trek," Rossall said.
Roddenberry also helped keep the franchise alive by inspiring fans and attended a major "Star Trek" convention each year, Rossall said.
"I think 'Star Trek' will always be her legacy," Rossall said.
"Star Trek" and its successors often focused on political and philosophical issues of the day. Roddenberry and her husband, who died in 1991, believed in creating "thoughtful entertainment" and were proud of the show and the passionate devotion of its fans, Rossall said.
"My mother truly acknowledged and appreciated the fact that 'Star Trek' fans played a vital role in keeping the Roddenberry dream alive for the past 42 years. It was her love for the fans, and their love in return, that kept her going for so long after my father passed away," her son said in a statement on the official Roddenberry Web site.
Born Majel Lee Hudec on Feb. 23, 1932, in Cleveland, Ohio, Roddenberry began taking acting classes as a child. She had some stage roles and then in the late 1950s and 1960s had bit parts in a few movies and small roles in TV series, including "Leave It to Beaver" and "Bonanza."
She met her husband in 1964 during a guest role for a Marine Corps drama he produced called "The Lieutenant." That same year, she was cast in the pilot for the "Star Trek" series as the no-nonsense second-in-command.
The pilot did not appeal to NBC executives and a second pilot was made, although portions of the original later showed up in a two-part episode called "The Menagerie."
The couple married in Japan in 1969 after "Star Trek" was canceled. After her husband's death, Roddenberry continued her involvement with the "Star Trek" franchise.
She also was the executive producer for two other TV science fiction series, "Andromeda" and "Earth: Final Conflict."