James R. Domengeaux, known as Jimmy Domengeaux (January 6, 1907 – April 11, 1988), was a lawyer from Lafayette, Louisiana, who served in the United States House of Representatives for Louisiana's 3rd congressional district from 1941 to 1949. He was a cultural activist of Cajun and Louisiana Creole descent who is best remembered for his efforts to preserve the French language in his native state.