A Green River Ordinance is a common United States city ordinance prohibiting door-to-door solicitation. Under such an ordinance, it is illegal for any business to sell their items door-to-door without express prior permission from the household. Some versions prohibit all organizations, including non-profit charitable, political, and religious groups, from soliciting or canvassing any household that makes it clear, in writing, that it does not want such solicitations (generally with a "No Trespassing" or "No Solicitations" sign posted).

The ordinance is named for the city of Green River, Wyoming, which in 1931 was the first city to enact it.^[1] The ordinance was unsuccessfully challenged on constitutional grounds by the Fuller Brush Company in 1932.^[2]