Police have arrested the driver of the vehicle, Gerald Massey, 28, of Antioch, in connection with the fatal collision.
At about 1:41 a.m. Antioch police received a report of a collision in the 3900 block of Delta Fair Boulevard.
When officers arrived at the scene, just west of Fairview Drive, they found one vehicle involved in the collision.
Police said the driver of the vehicle lost control. The vehicle then struck a tree in the center median and came to a stop on the south sidewalk of Delta Fair Boulevard.
A pedestrian was found trapped underneath the vehicle and pronounced dead at the scene, police said.
The driver of the vehicle was trapped inside the car and transported to a local hospital for treatment.