A chaika (Ukrainian: чайка, Serbian: Шајка / Šajka, Шајкe / Šajke) was a wooden boat with a mast and sail, a type of Galley, used by the:
- Zaporozhian Cossacks in the 16th–17th centuries in Ukraine on the Dnipro River and the Black Sea.
- Serbs in Vojvodina in the 16th-19th centuries on the Danube (Šajkaši) under Kingdom of Hungary, Austrian Empire and Habsburgs.