Mert Günok was born on 1 March 1989 in Istanbul, Turkey. He began his career at Galatasaray's youth academy and made his professional debut for the senior side in the late 2000s, serving as a back-up goalkeeper behind Volkan Demirel and Fernando Muslera across his first stint at the club.
He spent loan periods at Akhisar Belediyespor and several other Süper Lig clubs to accumulate competitive minutes before returning to the upper echelon of Turkish football. A move to Beşiktaş in 2015 gave him regular top-flight experience, and he returned to Galatasaray in 2018 where he eventually became the undisputed first-choice. He played a key role in Galatasaray's dominant runs in the Süper Lig in the early 2020s — the club claimed consecutive league titles in 2022-23 and 2023-24 — and was consistently one of the best shot-stoppers in the Turkish top flight.
For Turkey he made his senior debut in the 2010s and remained in the national squad picture for over a decade. He served as second-choice behind Şenol Güneş's preferred options for much of that period but earned recognition through dependable performances when called upon. He was part of the squad that reached the quarter-finals of UEFA Euro 2024 in Germany — Turkey's best run at a major European tournament in recent memory — and remained a senior option ahead of the 2026 World Cup.
Standing 1.88 m, Günok is a commanding goalkeeper with strong positional sense and confident handling under crosses. He has brought veteran calm to Galatasaray's title campaigns and helped reinforce Turkey's status as a competitive European nation capable of deep tournament runs.