| Martin Koscelník | |
| Birth Date: | 2 March 1995 |
| Birth Place: | Vranov nad Topľou, Slovakia |
| Height: | 1.79 m |
| Position: | Right-back |
| Clubnumber: | 3 |
| Youthyears1: | –2010 |
| Youthclubs1: | Futura Humenné |
| Youthyears2: | 2010–2014 |
| Youthclubs2: | Zemplín Michalovce |
| Years1: | 2015–2018 |
| Caps1: | 114 |
| Goals1: | 20 |
| Years2: | 2018–2022 |
| Caps2: | 97 |
| Goals2: | 3 |
| Years3: | 2022–2023 |
| Clubs3: | Rapid Vienna |
| Caps3: | 20 |
| Goals3: | 0 |
| Years4: | 2023– |
| Clubs4: | NAC Breda |
| Caps4: | 27 |
| Goals4: | 4 |
| Nationalyears1: | 2020–2022 |
| Nationalcaps1: | 14 |
| Nationalgoals1: | 1 |
| Club-Update: | 07:30, 8 June 2024 (UTC) |
| Nationalteam-Update: | 6 June 2022 |
Martin Koscelník (born 2 March 1995) is a Slovak professional footballer who plays as a right-back for Dutch club NAC Breda, and the Slovakia national team.
Koscelník made his Fortuna Liga debut for Zemplín Michalovce against AS Trenčín on 18 July 2015, only to be replaced in the second half by Martin Regáli.[1] On 29 August 2023, Koscelník signed a two-year contract with NAC Breda in the Netherlands.[2]
On 25 August 2020, Koscelník received his first call-up to the Slovak senior squad by coach Pavel Hapal for the Nations League matches against Czech Republic and Israel.[3] The same year on 4 September, he debuted in a 2020–21 UEFA Nations League match against neighbours Czech Republic.[4]
On 7 September 2021, Koscelník scored his first international goal in a 2022 FIFA World Cup qualifier against Cyprus, ending in a 2–0 victory for the Slovaks.[5]
As of match played on 29 March 2022. Scores and results list Slovakia's goal tally first.