| Clubname: | GS Marko |
| Fullname: | Γυμναστικός Σύλλογος Μαρκοπούλου «Μαρκό» |
| Upright: | 0.9 |
| Ground: | Municipal Markopoulo Stadium |
| Chairman: | Antonis Pikoulas |
| Manager: | Isidoros Stavrianos |
| League: | Gamma Ethniki |
| Season: | 2023–24 |
| Position: | Gamma Ethniki (Group 3), 6th |
Marko 1927 Football Club is a Greek football club based in Markopoulo, East Attica, Greece; playing in the Gamma Ethniki, Greek football's 3rd tier. Its colours are green and white. Its logo is a vine leaf in honour of the vineyards of Mesogeia area.