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.

He also has a career high ATP doubles ranking of World No.

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.