Palm Valley is a city in Cameron County, Texas, United States. The population was 1,413 at the 2020 census. It is part of the Brownsville…Palm Valley is a city in Cameron County, Texas, United States. The population was 1,413 at the 2020 census. It is part of the Brownsville–Harlingen–Raymondville and the Matamoros–Brownsville metropolitan areas.