== Masa muda ==
Mainoo dilahirkan di [[Stockport]], [[Manchester Rayа|Manchester Raya]], <ref>{{Cite web|title=Kobbie Mainoo|url=https://www.manutd.com/en/players-and-staff/detail/kobbie-mainoo|website=ManUtd.com|publisher=Manchester United|access-date=16 October 2022}}</ref> dan memulai karier pertamanya di Cheadle & Gatley Junior Football Club, sebelum akhirnya bergabung dengan [[Manchester United F.C.|Manchester United]] di umur sembilan tahun. <ref>{{Cite news|date=7 December 2022|title=Manchester United might be about to unleash their own future midfield star vs Cadiz|url=https://www.manchestereveningnews.co.uk/sport/football/football-news/man-united-kobbie-mainoo-news-25684009|work=Manchester Evening News|access-date=10 January 2023}}</ref> Mainoo adalah adik dari Jordan Hames, seorang pemeran dalam seri kelima serial ''Love Island'' . <ref>{{Cite web|date=9 December 2023|title=Fans are only just discovering who Kobbie Mainoo's older brother is|url=https://www.sportbible.com/football/football-news/man-utd/kobbie-mainoo-man-utd-premier-league-love-island-871387-20231209|website=SportBible|access-date=19 December 2023}}</ref>
== Karier klub ==
==== Musim 2022–23 ====
Pada bulan Mei tahun 2022, Mainoo menandatangani kontrak profesional pertamanya bersama Manchester United. <ref>{{Cite web|last=Fay|first=Richard|date=17 May 2022|title=Manchester United starlet Kobbie Mainoo signs first professional deal|url=https://www.manchestereveningnews.co.uk/sport/football/football-news/kobbie-mainoo-manchester-united-contract-23977503|website=Manchester Evening News|access-date=16 October 2022}}</ref> Penampilannya saat bertanding di kejuaraan [[Trofi EFL]] membuatnya dipanggil ke tim senior untuk berlatih pada bulan Oktober 2022. <ref>{{Cite web|date=11 October 2022|title=Manchester United wonderkid Kobbie Mainoo trains with first team ahead of Omonia clash|url=https://metro.co.uk/2022/10/11/manchester-united-wonderkid-kobbie-mainoo-trains-with-first-team-ahead-of-omonia-clash-17543147/|website=Metro.co.uk|access-date=16 October 2022}}</ref> Dia kemudian masuk ke daftar bangku cadangan untuk pertama kalinya pada tanggal 16 Oktober, pada pertandingan [[Liga Utama Inggris|Liga Premier]] melawan [[Newcastle United F.C.|Newcastle United]]. <ref>{{Cite web|last=Railston|first=Steven|date=16 October 2022|title=Who is Kobbie Mainoo? Meet the Manchester United youngster named on the bench vs Newcastle|url=https://www.manchestereveningnews.co.uk/sport/football/football-news/man-united-kobbie-mainoo-newcastle-25275884|website=Manchester Evening News|access-date=16 October 2022}}</ref>
Pada tanggal 10 Januari 2023 Mainoo menjalani debut seniornya di Manchester United, dimulai dengan kemenangan 3-0 [[Piala EFL 2022–2023|di Piala EFL]] atas klub [[Charlton Athletic F.C.|Charlton Athletic]].<ref>{{Cite news|last=Stone|first=Simon|date=10 January 2023|title=Manchester United 3–0 Charlton Athletic: Old Trafford side into Carabao Cup semi-finals|url=https://www.bbc.co.uk/sport/football/64149053|work=BBC Sport|access-date=10 January 2023}}</ref> Ia kemudian melakukan debut di pertandingan liga utama Inggris pada tanggal 19 Februari. Ketika itu ia masuk sebagai pemain pengganti dalam kemenangan 3-0 melawan klub [[Leicester City F.C.|Leicester City]]. <ref>{{Cite news|last=Kerr|first=Joshua|date=19 February 2023|title=Manchester United 3 Leicester City 0|url=https://www.manutd.com/en/news/detail/match-report-and-video-highlights-man-utd-v-leicester-city-premier-league-19-february-2023|work=Manchester United|access-date=20 February 2023}}</ref>
==== Musim 2023–24 ====
Mainoo turut serta dalam tur pramusim Manchester United tahun 2023-24 di Amerika Serikat.<ref>{{Cite news|last=Luckhurst|first=Samuel|date=19 July 2023|title=Manchester United confirm pre-season tour squad|url=https://www.manchestereveningnews.co.uk/sport/football/transfer-news/man-united-tour-squad-news-27355310|work=Manchester Evening News|access-date=19 July 2023}}</ref> Akan tetapi Mainoo mengalami cedera yang membuatnya absen pada awal musim tersebut. <ref>{{Cite web|last=Mamaniyat|first=Abdullah|date=18 August 2023|title=Erik Ten Hag provides Kobbie Mainoo injury timescale|url=https://reddevilarmada.com/2023/08/18/erik-ten-hag-provides-kobbie-mainoo-injury-timescale/|website=Red Devil Armada|language=en-US|access-date=20 September 2023}}</ref> Sekembalinya dari cedera, Mainoo memulai pertandingan liga pertamanya untuk Manchester United pada tanggal 26 November 2023. Pada pertandingan itu Manchester United meraih kemenangan 3-0 di kandang [[Everton F.C.|Everton]]. Ia kemudian memenangkan penghargaan man of the match di pertandingan tersebut.<ref>{{Cite web|title=Kobbie Mainoo: Man Utd youngster's full Premier League debut against Everton praised by Gary Neville and Roy Keane|url=https://www.skysports.com/football/news/11095/13017129/kobbie-mainoo-man-utd-youngsters-full-premier-league-debut-against-everton-praised-by-gary-neville-and-roy-keane|website=Sky Sports|language=en|access-date=26 November 2023}}</ref><ref>{{Cite web|last=Nelson|first=Joe|date=26 November 2023|title=Who was United's Man of the Match against Everton?|url=https://www.manutd.com/en/news/detail/kobbie-mainoo-wins-man-of-the-match-award-for-man-utd-performance-v-everton|publisher=Manchester United}}</ref> Ia kemudian melakukan debutnya [[Liga Champions UEFA|di Liga Champions]] pada tanggal 29 November. Ia masuk sebagai pemain pengganti pada menit ke-58, dalam pertandingan yang berakhir imbang 3–3 melawan klub Turki, [[Galatasaray S.K. (tim sepak bola)|Galatasaray]] . <ref>{{Cite web|date=29 November 2023|title=Galatasaray 3–3 Man Utd|url=https://www.theguardian.com/football/live/2023/nov/29/galatasaray-v-manchester-united-champions-league-live?page=with:block-65671c9f8f08e51ddd4b335e|website=The Guardian}}</ref>
Pada tanggal 28 Januari 2024, Mainoo mencetak gol pertamanya untuk Manchester United dalam pertandingan yang berakhir dengan kemenangan 4-2 di kandang [[Newport County A.F.C.|Newport County]] dalam pertandingan [[Piala FA 2023–2024|Piala FA]] putaran keempat.<ref>{{Cite web|date=28 January 2024|title=Newport County 2–4 Man Utd|url=https://www.bbc.co.uk/sport/football/68110828|website=BBC Sport}}</ref> Tiga hari setelahnya, pada tanggal 1 Februari, Mainoo kemudian mencetak gol pertamanya di Liga Premier dalam kemenangan yang berakhir dengan kemenangan dramatis 4–3 di kandang [[Wolverhampton Wanderers F.C.|Wolverhampton Wanderers]]. Kala itu ia mencetak gol kemenangan di menit ke-97, 5 menit sebelum pertandingan selesai. <ref>{{Cite web|date=1 February 2024|title=Wolverhampton Wanderers 3–4 Manchester United|url=https://www.bbc.com/sport/football/68090233|publisher=BBC Sport}}</ref>
== Karier internasional ==
Mainoo telah beberapa kali mewakili tim nasional Inggris, yakni di level U-17, U-18, dan U-19. <ref>{{Cite web|title=Kobbie Mainoo Internationals|url=https://www.worldfootball.net/player_summary/kobbie-mainoo/4/|website=worldfootball.net|access-date=24 November 2023}}</ref> Akan tetapi ia juga dapat mewakili tim nasional [[Tim nasional sepak bola Ghana|Ghana]].<ref>{{Cite news|date=17 May 2022|title=Kobbie Mainoo: All you need to know about Ghanaian midfielder who just signed a contract with Man Utd|url=https://www.ghanaweb.com/GhanaHomePage/SportsArchive/Kobbie-Mainoo-All-you-need-to-know-about-Ghanaian-midfielder-who-just-signed-a-contract-with-Man-Utd-1540400|work=ghanaweb.com|access-date=10 January 2023}}</ref>
== Gaya bermain ==
Mainoo merupakan seorang [[Gelandang (sepak bola)|gelandang tengah]] yang juga dapat bermain sebagai [[Gelandang (sepak bola)|gelandang serang]] dan [[Gelandang (sepak bola)|gelandang bertahan]].<ref name="position">{{Cite news|date=1 December 2023|title=Local hero: Kobbie Mainoo bringing cheer at troubled Manchester United|url=https://www.theguardian.com/football/2023/dec/01/local-hero-kobbie-mainoo-bringing-cheer-at-troubled-manchester-united|work=theguardian.com|access-date=2 February 2024}}<cite class="citation news cs1" data-ve-ignore="true">[https://www.theguardian.com/football/2023/dec/01/local-hero-kobbie-mainoo-bringing-cheer-at-troubled-manchester-united "Local hero: Kobbie Mainoo bringing cheer at troubled Manchester United"]. </cite></ref> Bekas pemain bertahan Manchester United [[Rio Ferdinand]] membandingkan gaya permainannya dengan [[Clarence Seedorf]] . <ref>{{Cite news|date=2 February 2024|title=Wolves 3-4 Man Utd: Kobbie Mainoo continues rise to stardom with 'dream' winning goal|url=https://www.bbc.co.uk/sport/football/68176430|work=BBC Sport|access-date=2 February 2024}}</ref>
== Penghargaan ==
|