Karol Ostrowski is a Polish sprint freestyle specialist. After making his junior international debut during the summer of 2017, Ostrowski gave his verbal commitment to Florida State to swim under Neal Studd. He currently trains at Miejski Klub Pływacki in Szczecin, Poland.
Ostrowski swam for Poland at the 2017 European Junior Championships in Israel where he won a gold medal as a member of the 4×100 meter freestyle relay. He also made the final in the 50 meter freestyle finishing 7th. A month later, Ostrowski was in Indianapolis for the World Junior Championships. He posted a 22.97 in the 50 meter freestyle final to finish 8th and swam a lifetime best of 49.87 to lead off Poland’s 4×100 meter freestyle relay to take the silver medal.