Leon Valley is a city in Bexar County, Texas, United States. Leon Valley is an enclave on the northwest side of San Antonio and is part of the San Antonio-New Braunfels Metropolitan Statistical Area. Leon Valley is an independent municipality surrounded by the city of San Antonio. Leon Valley city was developed in the 1940s as a farming community on Bandera Road between Helotes and San Antonio. Later in the year 1954 Leon Valley city is incorporated under the leadership of its founding mayor, Raymond Rimkus.