Shamrock Quay is a 255-berth marina on the west bank of the River Itchen in Southampton, roughly two miles upriver from Southampton Water.

It takes its name from the famous J-class yacht Shamrock V, which underwent her first refit at the site in 1967, and remains a working centre for boat building and refit, with numerous specialist trades on site.

Approaching by water, mariners proceed up Southampton Water, bear to starboard up the Itchen at Weston Shelf buoy, and observe the 6-knot speed limit. Shamrock Quay lies on the port side approximately 1,300 metres beyond the Itchen Bridge, opposite No.

5 green beacon. The marina monitors VHF Channel 80. It is operated by MDL Marinas and sits alongside sister facility Saxon Wharf, which houses the largest boat lift in Britain.