The big Valentine's Day event took place shortly after dawn in the main show tank of the theme park and produced a black-and-white bundle of joy 6 feet long and weighing an estimated 300-350 pounds.
Park officials told U-T San Diego the calf was born to Kasatka, a 37-year-old orca who was pregnant for 18 months.
Labor lasted about an hour and increased the number of killer whales at the San Diego park to 10.
The calf looked to be in good health but its gender wasn't immediately known. The public will probably get its first look at the baby in a few days, the newspaper said.