Osney Mill Marina is a small private marina situated on a 500-metre island in the River Thames in Oxford, England, accessed from the southern end of the island. The island was created in the Middle Ages to channel water to the now-disused Osney Mill.

The marina lies just off Mill Street, south of Botley Road, close to the site of Osney Abbey and within easy reach of Oxford railway station. The site offers around 40 moorings alongside the island, with electricity and water connections at each berth.

Boat maintenance and light engineering services are available on site. Osney Lock lies immediately to the north, making this a convenient access point onto the upper River Thames for boaters heading into or out of Oxford.