Ōami Station was opened on January 20, 1896, as the terminal station of the Bōsō Railway. The line was extended to Ichinomiya in 1897. The Tōgane Line began operations from June 30, 1900. On September 1, 1907, the Bōsō Railway was nationalized and became part of the Japanese Government Railways, which was transformed into the Japanese National Railways (JNR) after World War II. Freight operations were discontinued on July 1, 1971. On May 27, 1972, the station building was relocated to its present location, to eliminate the use of a switchback. The station was absorbed into the JR East network upon the privatization of JNR on April 1, 1987.