{{Geobox|River}}
The Calaveras River is a 51.9-mile (83.5 km) long river in Northern California in the United States. It drains part of the western Sierra Nevada foothills, flowing west across the agricultural San Joaquin Valley into the San Joaquin River at Stockton. The Calaveras River watershed drains 470 square miles (1,200 km2) and is primarily in Calaveras and San Joaquin Counties, although a small portion is in Stanislaus County. The river is a major source for irrigation water supply and groundwater recharge, and is dammed to form New Hogan Lake. The Spanish word calaveras means "skulls" and was given to the river in the early 1800s by explorers who found remains of numerous Native Americans along its banks.