El Oro () is a municipality in the Mexican state of Durango. The municipal seat lies at Santa MarÃÂa del Oro. The municipality covers an area of 10,041 km<sup>2</sup>.
As of 2010, the municipality had a total population of 11,320, up from 10,501 as of 2005.
The municipality had 113 localities, the largest of which (with 2010 population in parentheses) was Santa MarÃÂa del Oro (5,878), classified as urban.