The O'Day 40 is an American sailboat that was designed by C. Raymond Hunt Associates and Philippe Briand as a cruiser and first built in 1986.
C. Raymond Hunt Associates then took Briand's design and further developed it into the O'Day 40, with the addition of a suger-scoop transom and a revised interior.
It has a masthead sloop rig, a raked stem, a step-down reverse transom with a small swimming platform, an internally mounted spade-type rudder controlled by a wheel and a fixed fin keel or optional shoal draft keel.
[1][2] The boat is fitted with a Westerbeke 46 hp (34 kW) diesel engine for docking and maneuvering.
The head is located just aft of the bow cabin on the port side and includes a shower.