Eugene Preston Foster (April 4, 1848 – February 12, 1932), commonly known as E. P. Foster, was a rancher, entrepreneur, banker, and philanthropist in Ventura County, California. A native of Illinois, he moved to California and, in the early 1870s, settled in Ventura County. His early ventures included sheep ranching, managing a local water company, developing natural gas wells along the Ventura River, and planting and operating an apricot orchard. He then acquired an interest in the Bank of Ventura and served as its president from 1890 to 1917, when it was acquired by the Bank of Italy. He also invested in the Union Oil Company of California.