[2][3] Originally backing up Rüştü Reçber and Recep Biler, Demirel made his debut for the club on 26 April 2003.

After Reçber suffered an injury, Serdar Kulbilge took over as starting goalkeeper in favor of Demirel for the rest of the season.

[2][6] Demirel was the starting goalkeeper for the Fenerbahçe squad that progressed past the group stages of the 2007–08 UEFA Champions League.

[9] In 2014, just before the UEFA Euro 2016 qualifying match against Kazakhstan, Volkan Demirel left the Turkey national team after a dispute with a fan.

After Demirel's refusal to play with the national team, Volkan Babacan took over as the starter for the UEFA Euro 2016 Qualifiers.

On 2 September 2019, Fenerbahçe announced that Demirel was retired and would continue his career as an assistant coach in the team.

[14] On 30 October 2024, Bodrum appointed Demirel as the new head coach, following the departure of İsmet Taşdemir.