Oakdale is a city in Stanislaus County, California, United States.It is part of the Modesto Metropolitan Statistical Area. The city was founded in 1871 when the Stockton & Visalia Railroad met the Copperopolis Railroad. Oakdale goes by the slogan "Cowboy Capital of the World." The population was 20,675 at the 2010 census, up from 15,503 at the 2000 census.
The city is located in the east-central portion of the Central Valley, adjacent to the foothills of the Sierra Nevada. California State Routes 108 and 120 (Tioga Pass Road) intersect in the city.
According to the United States Census Bureau, the city has a total area of 6.1 square miles (15.8 km²), of which 6.0 square miles (15.7 km²) is land and 0.05 square miles (0.13 km²) (0.81%) is water.