Markos Kalovelonis (Greek: Μάρκος Καλοβελώνης, Марк Георгиевич Каловелонис; born 18 May 1994) is a Greek-Russian tennis player. Kalovelonis has a career high ATP singles ranking of World No. 445 achieved on 16 June 2016. He also has a career high ATP doubles ranking of World No. 187 achieved on 20 June 2022. Kalovelonis has won 21 ITF doubles titles. Kalovelonis has represented Greece at the Davis Cup where he has a W/L record of 6–5.He also represented Greece in the ATP Cup in 2020 and 2021.