The Grand River Conference, is a high school athletic conference comprising small-size high schools located in northwest and north central Missouri. The conference members are located in Andrew, Buchanan, Caldwell, Daviess, DeKalb, Gentry, Grundy, Harrison, Linn, Mercer, Putnam, Sullivan, and Worth counties.
Founded in December 1929, the conference was formed with six schools: King City, Stanberry, Maysville, Bethany, Albany and Grant City as the Grand River Six. By 1936, the conference had grown to eight teams. Various schools joined and dropped over the years, with several schools switching to 8-player football a contributing factor. By 2011, the conference had ten members, and by 2016, the conference was at 16 teams. On March 3, 2023, the superintendents of the conference voted to split into 2 separate conferences, Grand River Conference (GRC) and Grand River Conference West (GRC West), based on the previous divisional lines with Princeton joining the GRC West and giving the GRC the Brookfield Bulldogs (formerly of the Clarence Cannon Conference) and the Marceline Tigers (formerly of the Lewis & Clark Conference), who began GRC play in the 2024-2025 school year. On September 19, 2025, the GRC voted 8-1 to remove Polo from the conference at the end of the 2025-26 school year. Polo will become the third school in conference history to be dropped from the conference by the membership.
As of 2024, the Grand River Conference consists of eighteen high schools split into two separate conferences.
<nowiki>*</nowiki>Leaving the GRC after the 2025-2026 school year ends