The Battle of Ozyaty was fought on 18 June 1655 when a Polish-Lithuanian army crushed a Swedish relief force sent to the aid of Berestye Fortress (Brest, Belarus).
In June 1655, Polish counterattacks reconquered Halych from the Swedes, drove the invaders out of Lesser Poland, and threatened to recapture Swedish-occupied Belarus, namely the strongholds of Berestye and Minsk. A Swedish relief force sent to assist Berestye's garrison was crushed at the Battle of Brest on 18 June 1655. Later that same day, Arvid Vittenberg and his army marched to the city's relief, but they were intercepted by several Polish detachments led by Hetman Stefan Czarniecki. In the ensuing battle, the mercenary captain Jerzy Wisniewski was wounded while directing his party during a cavalry clash, but the Poles carried the day in his absence and destroyed Vittenberg's force.