| Thanasis Kostanasios | |
| Fullname: | Athanasios Kostanasios |
| Birth Date: | 11 January 1999 |
| Birth Place: | Piraeus, Greece |
| Height: | 1.79 m |
| Currentclub: | Giouchtas |
| Clubnumber: | 7 |
| Position: | Attacking midfielder |
| Youthclubs1: | Olympiacos |
| Years1: | 2018–2020 |
| Caps1: | 1 |
| Goals1: | 0 |
| Years2: | 2020–2022 |
| Caps2: | 50 |
| Goals2: | 7 |
| Years3: | 2022–2023 |
| Caps3: | 4 |
| Goals3: | 1 |
| Years4: | 2023 |
| Clubs4: | → Egaleo (loan) |
| Caps4: | 12 |
| Goals4: | 2 |
| Years5: | 2023– |
| Caps5: | 10 |
| Goals5: | 0 |
| Nationalyears1: | 2014 |
| Nationalcaps1: | 1 |
| Nationalgoals1: | 0 |
| Nationalyears2: | 2015–2016 |
| Nationalcaps2: | 8 |
| Nationalgoals2: | 1 |
| Nationalyears3: | 2017 |
| Nationalcaps3: | 5 |
| Nationalgoals3: | 2 |
| Nationalyears4: | 2017 |
| Nationalcaps4: | 9 |
| Nationalgoals4: | 1 |
| Nationalyears5: | 2018 |
| Nationalcaps5: | 2 |
| Nationalgoals5: | 0 |
| Pcupdate: | 1 May 2022 |
| Ntupdate: | 11 January 2018 |
Athanasios 'Thanasis' Kostanasios (Greek, Modern (1453-);: Αθανάσιος 'Θανάσης' Κωστανάσιος; born 11 January 1999) is a Greek professional footballer who plays as an attacking midfielder for Super League 2 club Giouchtas.
Born in Piraeus, Kostanasios came through the academy of Olympiacos, featuring for the club’s Under-19 and Under-20 team and making one first team appearance in a Super League 1 match in May 2018. From Olympiacos, Kostanasios would join Super League 2 side Ergotelis, where he made 51 appearances with seven goals across two seasons.
In July 2022, Kostanasios joined Athens Kallithea FC.[1]
At international level, Kostanasios earned 26 caps with five goals representing Greece from the Under-16 to Under-20 levels.