One ticket with all six numbers was sold at Jennifer’s Gift Shop in San Jose.
The numbers drawn were 8, 14, 17, 20, 39 and the Megaball number was 7.
The estimated jackpot was $636 million, the second-largest lottery prize in U.S. history.
The drawing was the 22nd since the last time a ticket with all six numbers was sold.
The Mega Millions game is played in 43 states, the District of Columbia and U.S. Virgin Islands.
Lottery officials urged winners to immediately sign the back of the tickets in ink and claim the prizes at the nearest California Lottery district office.