Atascadero is located in San Luis Obispo Coun just north of San Luis Obispo between San Luis Obispo and Paso Robles along US Highway 101 on the banks of the
Salinas River near Santa Margarita Lake and the Pacific Ocean.
The population estimate for July 1, 1998 was 24,636, an increase of 1,498 since 1990.
Atascadero is part of the San Luis Obispo-Atascadero-Paso Robles metro area.