Oakdale is a large village in Caerphilly county borough, Wales, 9½ miles north of Caerphilly itself, within the historic boundaries of Monmouthshire. Situated in the Sirhowy valley, it is 1.5 miles (2.4 km) east of Blackwood, with which it forms a conurbation. At the 2001 census Oakdale had a population of 4,478.