Truesdale is a city in Buena Vista County, Iowa, United States. The population was 69 at the time of the 2020 census. The Truesdale pos…Truesdale is a city in Buena Vista County, Iowa, United States. The population was 69 at the time of the 2020 census. The Truesdale post office opened in 1900. Truesdale is located at 42°43′43″N 95°10′59″W / 42.72861°N 95.18306°W.