| Themistoklis Tselios | |
| Birth Date: | 6 October 1997 |
| Birth Place: | Athens, Greece |
| Height: | 1.83 m |
| Position: | Goalkeeper |
| Currentclub: | Niki Volos |
| Youthclubs1: | AEK Athens |
| Years1: | 2015–2016 |
| Clubs1: | Sparta |
| Years2: | 2016–2017 |
| Clubs2: | AO Zevgolatiou |
| Years3: | 2017–2018 |
| Clubs3: | Panargiakos |
| Years4: | 2018–2019 |
| Clubs4: | Aittitos Spata |
| Caps4: | 2 |
| Goals4: | 0 |
| Years5: | 2019–2021 |
| Clubs5: | Diagoras |
| Caps5: | 45 |
| Goals5: | 0 |
| Years6: | 2021–2022 |
| Clubs6: | Ergotelis |
| Caps6: | 30 |
| Goals6: | 0 |
| Years7: | 2022–2024 |
| Caps7: | 39 |
| Goals7: | 0 |
| Years8: | 2024– |
| Caps8: | 0 |
| Goals8: | 0 |
| Nationalyears1: | 2014 |
| Nationalcaps1: | 2 |
| Nationalgoals1: | 0 |
| Nationalyears2: | 2016 |
| Nationalcaps2: | 3 |
| Nationalgoals2: | 0 |
| Pcupdate: | 15 June 2023 |
| Ntupdate: | 29 March 2016 |
Themistoklis Tselios (Greek, Modern (1453-);: Θεμιστοκλής Τσέλιος; born 6 October 1997) is a Greek professional footballer who plays as a goalkeeper for Super League 2 club Niki Volos.
On 8 July 2021, Greek Super League 2 club Ergotelis announced the signing of Tselios, on a two-year contract.[1]
His twin brother, Ilias, is also a professional footballer.