[3] The station consists of an island platform serving 2 tracks.

A siding branches off track 1 and ends in a large vehicle shed near the station building.

[2][4][5] In addition, a shop near the station sells some types of tickets as a kan'i itaku agent.

[6] Oshima Station was opened on 25 March 1914 as one of several intermediate stations built when Japanese Government Railways (JGR) extended the track of the Tokushima Main Line from Awa-Yamakawa to Awa-Ikeda.

With the privatization of Japanese National Railways (JNR), the successor to JGR, on 1 April 1987, Oshima came under the control of JR Shikoku.