The Star keelboat is a 6.9 metres (23 ft) one-design racing keelboat for two people designed by Francis Sweisguth in 1910.

The Star was an Olympic keelboat class from 1932 through to 2012, the last year keelboats appeared at the Summer Olympics at which Ireland's representatives were Peter O'Leary and David Burrows.

Ireland has performed well in the class internationally thanks to some Olympic campaigns including a bronze medal at the Star World Championships in 2000, won by Mark Mansfield and David O'Brien.

The boat is sloop-rigged, with a mainsail larger in proportional size than any other boat of its length. Unlike most modern racing boats, it does not use a spinnaker when sailing downwind. Instead, when running downwind a whisker pole is used to hold the jib out to windward for correct wind flow.

Early Stars were built from wood, but modern boats are of fibreglass and carbon construction.

The boat must weigh at least 671 kg (1,479 lb) with a maximum total sail area of 26.5 m2 (285 sq ft).

The Star class pioneered an unusual circular boom vang track, which allows the vang to effectively hold the boom down even when the boom is turned far outboard on a downwind run.

Another notable aspect of Star sailing is the extreme hiking position adopted by the crew and at times the helmsman, who normally use a harness to help hang low off the windward side of the boat with only their lower legs inside.