| Marios Kostoulas | |
| Birth Date: | 12 March 1996 |
| Birth Place: | Larissa, Greece |
| Height: | 1.84 m |
| Currentclub: | Kalamata |
| Clubnumber: | 23 |
| Position: | Defensive midfielder |
| Youthclubs1: | Atromitos |
| Years1: | 2016–2019 |
| Clubs1: | Atromitos |
| Caps1: | 0 |
| Goals1: | 0 |
| Years2: | 2016–2017 |
| Clubs2: | → Agios Ierotheos (loan) |
| Years3: | 2017 |
| Clubs3: | → Ionikos (loan) |
| Years4: | 2018–2019 |
| Clubs4: | → Iraklis (loan) |
| Caps4: | 14 |
| Goals4: | 0 |
| Years5: | 2019–2020 |
| Clubs5: | Apollon Larissa |
| Caps5: | 2 |
| Goals5: | 0 |
| Years6: | 2020–2021 |
| Clubs6: | Diagoras |
| Caps6: | 17 |
| Goals6: | 0 |
| Years7: | 2021–2023 |
| Clubs7: | Iraklis |
| Caps7: | 47 |
| Goals7: | 2 |
| Years8: | 2023– |
| Clubs8: | Kalamata |
| Caps8: | 0 |
| Goals8: | 0 |
| Pcupdate: | 15 June 2023 |
Marios Kostoulas (el|Μάριος Κωστούλας; born 12 March 1996) is a Greek professional footballer who plays as a defensive midfielder for Super League 2 club Kalamata.