Arsenal in 2015 At first Kamara joined up with the club's
academy. He went on to be an unused substitute for Arsenal's
UEFA Champions League match against
Galatasaray in December 2014. Kamara made his only appearance for Arsenal a day before his 20th birthday on 27 October 2015, up against
Sheffield Wednesday in the
EFL League Cup fourth round in an eventual 3–0 away loss; he started the match and was substituted for
Krystian Bielik after an hour. On 22 January 2016, Kamara returned to Southend in
League One, on loan for the rest of the season. He played six matches, all but one as a starter. On deadline day of the summer transfer window, 31 August 2016, Kamara joined
Colchester United in
League Two on loan until January 2017. He played six times, starting just once in the league.
Dundee On 13 July 2017, Kamara signed a two-year deal with
Dundee. He made his debut for the club in a
Scottish League Cup game away to
Raith Rovers where he put in a man of the match performance.
Rangers On 5 January 2019, Kamara signed a pre-contract with
Rangers on a four-and-a-half-year deal. On 31 January, this deal was brought forward when the two clubs agreed to a £50,000 transfer. He scored his first goal in senior club football on 27 February 2019, opening a 4–0 home win over his former club Dundee. On 18 March 2021, Kamara accused
Slavia Prague player
Ondřej Kúdela of racist verbal abuse during a
Europa League knockout match. Kúdela denied the claims of racism and claimed that after the match Kamara physically assaulted Kúdela in the stadium tunnel in front of
UEFA officials and Rangers manager
Steven Gerrard. Ahead of the
Old Firm derby,
Celtic and Rangers players stood side by side in support of Kamara. On 14 April, UEFA officially found both Kamara and Kúdela guilty. Kúdela was banned for racial abuse for 10 UEFA matches, while Kamara was handed a three-match ban for assault. On 22 September 2021, Kamara signed a new four-year contract with the club that would see him remain with the club until the summer of 2025. Days later, he was sent off away to
Sparta Prague, a game in which his every touch was booed by the mostly underaged audience in relation to the Kúdela abuse; UEFA found insufficient evidence of a racial motive and did not punish the club. Kamara was an integral part of the Rangers squad in the club's
2021–22 UEFA Europa League campaign. He scored an important goal against
RB Leipzig in the second leg of the semi finals, and helped Rangers to reach to the finals of the competition, where they eventually fell short to
Eintracht Frankfurt losing on penalties.
Leeds United On 31 August 2023, Kamara signed a four-year deal with
English club
Leeds United for an undisclosed fee. However, the transfer fee was reported in media to be around £5.5 million. He became the fifth Finnish player to sign for Leeds after
Sebastian Sorsa,
Mika Väyrynen,
Mikael Forssell and
Aapo Halme. Kamara made his debut for Leeds in the
EFL Championship on 2 September 2023, as a late substitute in a 0–0 home draw against
Sheffield Wednesday. On 18 February 2024, after his first 25 matches in Championship, Kamara had a successful passing rate of 93.5%. Leeds finished 3rd in the Championship table and advanced to the
promotion play-off final, where they eventually fell short to
Southampton.
Rennes On 16 July 2024, Kamara joined
Ligue 1 club
Rennes for a reported €10 million fee, signing a deal until June 2028.
Al Shabab On 31 January 2025, Kamara was loaned out to
Saudi Pro League club
Al Shabab, becoming the first Finnish player in the Saudi league. ==International career==