José María Estudillo (died April 8, 1830) was a Spanish-born Californio military officer and early settler of San Diego.

He is the founder of the Estudillo family of California and served as Commandant of the Presidio of San Diego.

The house is still standing, known as Casa de Estudillo, and is one of the oldest surviving buildings in California.

It is located in Old Town San Diego State Historic Park, on the southeast side of the Old Town San Diego plaza, and is designated a National Historic Landmark in its own right.

In December 1823 he was diarist with Brevet Captain José Romero when they were sent to find a route from Sonora (Mexico) to Alta California; on their expedition they first recorded the existence of Agua Caliente (hot water) at Palm Springs, California.