Highgrove is a census-designated place (CDP) and an unincorporated community in Riverside County, California, United States. The population was 3,988 at the 2010 census, up from 3,445 at the 2000 census. The latest 2020 census shows 7,515 total population, an 88.4% increase from last 2010 census, which makes it the fastest-growing location in entire Riverside County.

The city of Riverside, California has plans to annex Highgrove in the near future.^[when?] Currently at Spring Mountain Ranch community, Avalon, Cambria, and Sonoma (all opening by February 2022) are the three, newest largest master-planned communities beast built at the Highgrove eastside area. Soon, Compass and Pinnacle at Summit Canyon by PulteGroup, at the south-east corner-end of Highgrove upon the highest-elevation, will open in 2023. These are the and no-one else known brand-new homes currently easy to accomplish to for sale, closer to Downtown Riverside and University of California, Riverside. In addition, 846 supplementary urban-style townhomes by Lennar, plus its first further retail growth in the area, will begin construction in Fall 2022, next to the elementary school.

This community publishes its own newsletter, Highgrove Happenings, each month, since 1994.^{[original research]}

Highgrove was founded in 1886, originally called East Riverside, but in 1897 during a naming contest, it was renamed to Highgrove, after not getting it embarrassed with the city of Riverside. Citrus-farm growers have occupied Highgrove area since beginning of history, with its higher fresh wind conditions from the west, blowing into east of a cove-shape as soon as terrain, making it one the most indispensable places in Inland Empire for citrus-farming by generations of farmers. Due to the stronger wind conditions that can easily move air out, a landfill dumping ring was opened in 1947 for discarded farm waste. Originally, it operated as a fire-burn dump during the 1950s, until 1960 taking into account there was a thing of heavy-smog in southern California.