Omega (originally, Delerium Tremens) was a former settlement in Nevada County, California, United States, first populated in 1850 by a single miner, J.A. Dixon, working a claim during the California Gold Rush. The town was located east-southeast of the present-day unincorporated town of Washington, California. A sister town, Alpha, located at what is now the site of the historical Omega Hydraulic Diggings, was about north of Omega. In the mid 1850s, following the introduction of hydraulic mining operations nearby, the town prospered. Omega had a post office (which operated from 1857 to 1891), and needed to convert a residence into a jail in late 1858.