Šibenik Ademi began his career at
Šibenik where he was promoted to the first team on 15 September 2007. He made his first senior appearance for the club on 22 March 2008 in a match against
Dinamo Zagreb. He was also the youngest player that captained any Prva HNL club that season.
Dinamo Zagreb On 16 June 2010 he was transferred to Dinamo Zagreb for a fee of €400,000. He made his first appearance for his new club on 31 July 2010 in a league match against
Rijeka in a match Dinamo Zagreb lost 2–1. He also made his debut in
European competitions on 4 August in the
2010–11 UEFA Champions League third qualifying round match against
Sheriff Tiraspol which finished with a draw 1–1. Upon arrival of the coach
Vahid Halilhodžić he established himself as a first team regular in the position of defensive midfielder, and appeared as a starter in their
2010–11 UEFA Europa League group matches, as Dinamo finished third with 7 points, behind
Villarreal and
PAOK. By the end of the season he has won his first trophies with Dinamo,
Prva HNL and
Croatian Cup. After losing his first team spot, in the second part of the
2011–12 season he was sent on loan to
Lokomotiva, where he made only three appearances due to injury. He came back from loan at the beginning of the
2012–13 season, and was a part of the squad that qualified for the
2012–13 UEFA Champions League. In the CL group stage, Ademi made 5 appearances, as Dinamo finished bottom of their group with one point. On 7 October 2015, Dinamo Zagreb announced that Ademi failed a
doping test after their recent
Champions League win over
Arsenal in September.
UEFA subsequently suspended Ademi for a period of four years. On 27 March 2017, the suspension was reduced by two years as Ademi managed to prove that he hadn't taken doping intentionally, making him eligible for selection from October 2017. In November 2017, Ademi was named the club captain, after coach
Mario Cvitanović stripped
Domagoj Antolić of captaincy. In summer 2020, upon winning
Prva HNL, Ademi became the most decorated player in Dinamo's history, having won 17 trophies. On 3 December 2020, he broke
Sammir's record for most appearances for Dinamo in European competitions, making his 77th appearance in the 2–0
Europa League victory over
Feyenoord at
De Kuip.
Beijing Guoan In March 2023, it was confirmed that Ademi would be leaving Dinamo after 13 years to join
Chinese Super League club
Beijing Guoan. He played his final match for Dinamo on 19 March against
Rijeka. Ademi scored his first goal for Guoan in his 7th game for the club against Nantong Zhiyun on 15 May 2023.
Return to Dinamo Zagreb On 8 September 2023, Ademi rejoined Dinamo Zagreb. ==International career==