Leonie Antonia Beck (born 27 May 1997) is a German swimmer. She competed in the women's 800 metre freestyle event at the 2016 Summer Olympics.
At the 2022 European Aquatics Championships, held in Rome, Italy with open water swimming at Ostia in August, Beck won the gold medal in the 10 kilometre open water swim with a time of 2:01:13.4.
As part of the 2023 FINA Open Water Tour, Beck first won the gold medal in the 10 kilometre open water swim at the first leg, in Egypt in early May, with a time of 2:04:05.60 before following up with a gold medal victory also in the 10 kilometre swim on 20 May at the second leg, held in Golfo Aranci, Italy, with a time of 1:56:17.40.