River Grove is a village in Cook County, Illinois, United States. The population was 10,227 at the 2010 census.
Just like nearby Elmwood Park and Oak Park are named after their historic elm and oak trees, River Grove gets its two-part name first from the community's shallow muddy plains river, and second from the majestic groves of American ash trees lining shore of the (Aux) Des Planes River "Bottomland". Credit goes to the village's early German and Nordic settlers who, already holding a great reverence for the "Mystic Ash" through old world traditions, felt that they were home again among the familiar groves of ash trees, "just like the ones they left behind". Up until the modern day extinction event of the American ash tree species 2006–2018, River Grove was the home to Cook County's second-oldest Green Ash with an estimated age of 240 in the "Old growth" Lafrombose Woods, along with several other living examples of locally evolved White, Green, Black and Blue Ash types 110–160 years of age scattered around the village.