Alcyon may refer to:
Aircraft Morane-Saulnier Alcyon, a French trainer introduced in 1949
Companies Alcyon a French bicycle, car and motorcycle manufacturer in business 1903–54
Ships , a LAdroit-class destroyer in service with the French Navy 1929–52 , a French fishing trawler in service 1904–40, requisitioned by the Kriegsmarine and served as the harbour defence boat Boot 10 Alcyon 1940–41, and the vorpostenboot V 420 Alcyon 1941–43
See also Alcyone (disambiguation)