Eupen Onyekuru began his football career with the
Aspire Academy in 2010, and graduated in 2015 joining their partner club,
K.A.S. Eupen. He made his debut for Eupen on 5 September 2015 in a 2–2 tie against
K.F.C. Dessel Sport in the
Belgian Second Division. Onyekuru helped the team get promoted to the
Belgian First Division A in his debut season, and made his professional debut in a 3–0 loss on 30 July 2016 against
S.V. Zulte Waregem. After a successful season in the Belgium first division, Onyekuru finished as one of the top scorers in the league, catching the attention of various larger teams in Europe. He finished the 2016–17 season as joint top-scorer with 22 goals, but the trophy was handed to
Łukasz Teodorczyk as he scored more away goals than Onyekuru.
Everton On 30 June 2017, Onyekuru joined
Everton for £7 million and was immediately sent on loan to
Anderlecht. Onyekuru had been handed the number nine jersey at Anderlecht for the 2017–18 campaign. Having scored 10 goals in 28 matches for Anderlecht, Onyekuru suffered a knee ligament injury in December which would require surgery. Anderlecht announced surgery would be necessary and that he would be out of action "for several months". In January 2018, it was reported that Onyekuru would return to Anderlecht after rehabilitation and full recovery.
Loan to Galatasaray In July 2018, Onyekuru joined
Galatasaray on a season-long loan. The loan fee paid to Everton was reported as £700,000. On 20 May 2019, Onyekuru was on the scoresheet for Galatasaray as they defeated title challengers
İstanbul Başakşehir 2–1 to secure the
Süper Lig championship for the second straight season. The victory also meant that Galatasaray secured the domestic double having defeated
Akhisar Belediyespor in the
Turkish Cup final the week prior.
Monaco Having failed to ever secure a work permit in the UK, Onyekuru joined
AS Monaco on a permanent transfer on 12 August 2019. The fee was undisclosed (rumoured to be between £12-£15 million) and Onyekuru signed a five-year deal with the
Ligue 1 club.
Return to Galatasaray on loan On 5 January 2020, Onyekuru signed for
Galatasaray, his former club, on a six-month loan with no option to buy. He left after his loan ended in June, making a total of twelve appearances and scoring one goal. On 25 January 2021, Onyekuru once again signed for Galatasaray on a six-month loan, this time with an option to buy.
Olympiacos On 2 August 2021,
Olympiacos announced the signing of Onyekuru for a four-year deal for an undisclosed amount.
Al-Fayha On 11 August 2023, Onyekuru joined
Saudi Pro League club
Al-Fayha on a two-year contract.
Gençlerbirliği On 23 July 2025, Onyekuru joined Süper Lig club
Gençlerbirliği on a free transfer. ==International career==