Demir was born in Araklı, Trabzon. His family moved to Karadeniz Ereğli, Zonguldak when Demir was five years old. He has four brothers: two older and two younger twins. His younger brothers play for the Bursasporyouth team. Demir played for his school team before Karadeniz Ereğli Belediyespor signed him to a youth contract in 2002. When asked what his goals were as a footballer, Demir replied "I didn't have any goals when I started playing football. It was just a game for me, but then I was signed to Karadeniz Ereğli Belediyespor. It was then I started thinking of what I wanted to accomplish... I wanted a better life for my family." Demir's favorite footballer is Fatih Tekke, a fellow striker from Trabzon. Sedat Özden, a former professional football player who played for Bursaspor, spotted Demir at a youth tournament in Ankara. He became interested in bringing Demir to Bursa after he helped lead Karadeniz Ereğli Belediyespor to the championship. Bayram Altıntaş, Demir's coach at Karadeniz Ereğli Belediyespor, offered Demir to Bursaspor. The club signed Demir to a youth contract at age 12. Due to his small stature and differences between his small hometown and the more modern, bustling city of Bursa, Demir quickly became homesick. After spending one month with Bursaspor, he packed his bags and returned home. Although he was highly coveted by the coaches in Bursa, Demir was reluctant to return. It was then that his father told him "go there and finish school. If you don't want to become a footballer, then at least finish school and come home." Demir described his first season as a bad one. He said his teammates couldn't believe he was given a chance to play due to his bad form. However, his coach Yılmaz Burul believed in Demir's abilities and pushed him forward. Demir was named captain the following season. He has scored 17 goals in 27 A2 matches.
Club career
Demir joined Bursaspor in 2005 and signed a professional contract in 2007. He made his first appearance in the Süper Lig in the final game of the 2008–09 season, coming off the bench in the 86th minute against Gaziantepspor. Demir regularly trains with the senior squad, but has not been able to play many games due to injuries. Chelsea and West Ham courted Demir and made offers after he scored two goals against Russia in a youth national team match. Bursaspor turned both offers down, stating that it was too soon for Demir to leave the club. He has stated that he does not want to play for an Istanbul club such as Fenerbahçe or Galatasaray, but move abroad instead. After refusing to sign a new deal with his current club Bursaspor, he was sent to Gaziantepspor in January 2011. In the last day of the transfer period he accepted to sign a contract with Gaziantepspor for four and a half years. On 2 July 2019, Demir joined İstanbul Başakşehir on a four-year deal. On September 3, 2019, he has signed a season long loan deal with Gazişehir Gaziantep.
