Police said they found the two with gunshot wounds inside a home in the 800 block of Railroad Street.
The woman was pronounced dead at the scene and the man was in stable condition at a hospital. Their identities have not been released.
No arrests have been made and a motive has not been determined.
A neighbor said a couple and their three children live in the home where the fatal shooting happened.
Anyone with information was asked to call the Corona Police Department at (951) 817-5837.