Wildomar is a city in southwest Riverside County, California, United States. The city was incorporated on July 1, 2008. As of the 2020 census, the population was 36,875. The community has grown very quickly during the early twenty-first century; the population has more than doubled since the 2000 census, when the community was still an unincorporated census-designated place.

In the summer of 1880 when, looking down from the peak of Mt. Baldy, Franklin Heald of Pasadena first noticed Lake Elsinore, then known as La Laguna. A few months later, in October, Frank Kimbal of San Diego signed an agreement with the Atchison, Topeka and Santa Fe Railroad to build a rail line past the lake from San Diego to Barstow, then known as Waterman.