The Battle of Oliwa, also known as the Battle of Oliva or the Battle of Gdańsk Roadstead, was a naval battle that took place on 28 November, 1627, slightly north of the port of Gdańsk off of the coast of the village of Oliva during the Polish–Swedish War. It was the largest naval engagement to be fought by the Polish–Lithuanian Commonwealth Navy and resulted in defeating a Swedish squadron led by Niels Stiernsköld that conducted a blockade of the harbour of Gdańsk. The Poles sailed out of the Gdańsk harbour and engaged the Swedish squadron capturing the Swedish flagship and sinking another Swedish warship.