|Full name||Markos Vellidis|
|Date of birth||4 April 1987|
|Place of birth||Kastoria, Greece|
|Height||1.83 m (6 ft 0 in)|
|2006–2007||→ Koropi (loan)||17||(0)|
|2007–2008||→ Diagoras (loan)||36||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 2 March 2014.
† Appearances (Goals).
Vellidis began his career by signing with Panathinaikos F.C. in August 2005. In 2006-07 season, he went on loan to Koropi, with playing in 17 matches. The next season, he went on loan to Diagoras F.C., and played in 36 matches.
In 2008, Diagoras bought Vellidis from Panathinaikos. He made 55(91 total) league appearances for Diagoras. He was a good penalty-stopper and was popular with fans. There was minor interest from some teams, but the biggest was by Aris Thessaloniki F.C.. Diagoras' fans were very proud for their goalkeeper, because they wanted Markos to show his talent and value in a big team. And this team, was Aris. Vellidis made his dream fact, and signed with a team with many success in Greece and Europe.
His very good appearances for Diagoras were rewarded by a signing with Aris F.C. in 15 June 2010, getting the number 1.
In the 2010-2011 season, Vellidis played 4 matches for Aris F.C., bringing good performances. These performances were the reason for that Vellidis was recommended as a great talent and also was known that behind Sifakis was another very good goalkeeper.
In the 2011-2012 season, first choice goalkeeper of Aris, Michalis Sifakis, had medical problems, which sidelined him for 5–8 months. Vellidis played his first of the season in 2 October 2011 against Skoda Xanthi in Kleanthis Vikelidis, giving a fine performance, with having a clean sheet. Since then, Vellidis is the first goalkeeper in the team. This season was the best of Vellidis's career so far.
Aris was in difficult times, but Vellidis was one of those who stayed loyal to Aris. He was the first choice goalkeeper and the fans wanted he to stay for a lot years. He is the young star of Aris, along with Giannis Gianniotas. He had an argue with coach Makis Katsavakis just before the match against Panionios in Kleanthis Vikelidis Stadium. However, it was decided that Vellidis will stay in team.
Vellidis signed for PAS Giannena on 13 June 2013 on a 2-year contract.