Markus Zillner (born 19 March 1970) is a former professional tennis player from Germany.

[1] Zillner was runner-up in the 18s age group of the 1987 German Open.

[2] He made the quarter-finals of the 1991 Austrian Open, held in Kitzbühel.

[2] En route he defeated the eighth ranked player in the world, Sergi Bruguera.

[3] The German met Nicklas Kulti in the second round and played another five set match, but this time wasn't able to finish on top.