Vainius or Voin (died between 1338 and 1342) was the Lithuanian Prince of Polotsk from 1315 to his death.
[1] Very little is known about Vainius, brother of Gediminas, Grand Duke of Lithuania.
In 1328 he, already as Prince of Polotsk, signed a treaty with the Livonian Order and Novgorod.
[1] His only known son Liubartas died in 1342 during fights with the Livonian Order.
This biographical article about a member of the Lithuanian nobility is a stub.