The Town of Danville is located in the San Ramon Valley in Contra Costa County, California, United States. It is one of the incorporated municipalities in California that use "town" in their names instead of "city". The population was 43,582 at the 2020 census. Since 2018, for five years in a row, Danville was named "the safest town in California". The Iron Horse Regional Trail runs through Danville. It was first a railroad that has been converted to an 80-foot (24 m) wide corridor of bike and hike trails as well as controlled intersections. Extending from Livermore to Concord, the trail passes through Danville. Danville is also home to the Eugene O'Neill National Historic Site, Village Theatre and Art Gallery, and the Museum of the San Ramon Valley.