Mongeau () is a French-language surname. Notable people with the name include:
Claude Mongeau, Canadian railroad executive France Mongeau (born 1961), Canadian educator and poet Michel Mongeau (ice hockey) (1965–2010), Canadian ice hockey player Michel Mongeau (actor) (–2020), Canadian actor Serge Mongeau (born 1937), Canadian physician, writer, publisher and politician Tana Mongeau (born 1998), American Internet personality and model