Üstündağ's father was a worker in Anadolu Glass Industry factory and his mother was a housewife.

[3] He first became noted with his role on ATV series Yersiz Yurtsuz alongside Ferdi Tayfur.

In the movie Zeynep'in Sekiz Günü, he portrayed a trickster named Ali.

His breakthrough came with a role in the series Kurtlar Vadisi Pusu, in which he played the character of Muro.

His performance in Muro: Nalet Olsun İçimdeki İnsan Sevgisine received critical acclaim.