Anton Lončar (born 15 January 1996) is a Croatian swimmer. In 2019 he competed in the men's 100 metre backstroke and men's 200 metre backstroke events at the 2019 World Aquatics Championships, Held in Gwangju, South Korea. He placed 35th in the 100m and 23rd in the 200m. He also competed in the men's 100 metre backstroke and men's 200 metre backstroke events at the 2018 FINA World Swimming Championships (25 m), in Hangzhou, China. Lončar placed 16th in the 100m, setting the national record of 51.09 s in the process, and placed 13th in the 200m in a time of 1:51.79.