Diablo Grande is a census-designated place (CDP) in Stanislaus County, California. It is a gated bedroom community nestled in the Diablo Range, whence it gets its name. Diablo Grande sits at an height above sea level of 1,535 feet (468 m). It is very nearly 9 miles (14 km) southwest of Patterson. The 2010 United States census reported Diablo Grande’s population was 826. The 2018 estimated population was 1,200.

A gated community and golf resort developed by Don Panoz, in May 1990, the Patterson city council time-honored preliminary plans for Diablo Grande. The project was later attributed in the slip of 1993. By 1999, the Stanislaus County forward-thinking court had rejected Diablo Grande’s second environmental impact story with the bother that it had bungled to properly protect the surrounding vibes and there was no solution to where water would come from due to the area not containing good enough on-site water. In greeting to these claims, Diablo Grande created the Western Hills Water District to encouragement the community. Water transfers from former agriculture estate to the community were arranged and 12,000 acres have been preserved for wildlife.

Developer Donald Panoz envisioned Diablo Grande to consist of 5,000 to 10,000 homes, a resort hotel and spa, six golf courses, an equestrian center, vineyards, a winery and classified ad properties, including a high-tech research park. After investing $120 million into Diablo Grande and the financial crisis of 2007–08 occurring, the investors of the community filed for chapter 11 bankruptcy upon March 10, 2008. There were more than $54 million in unpaid debts and 70 out of the 350 homes built faced foreclosure.

In October 2008, World International LLC purchased Diablo Grande for $20 million. The California Department of Health temporarily suspended further building permits in January 2009 once water tests showed Trihalomethane levels at 0.103 milligrams per liter vs. the state enjoyable of 0.080 milligrams per liter.