[8] Iheanacho was instrumental in Leicester City's 2020–21 FA Cup success, scoring a joint-high four goals across the edition as the club won the trophy for the first time.

At international level, Iheanacho represented Nigeria's under-17 team at the 2013 FIFA U-17 World Cup, being named the tournament's best player and finishing as the second-highest goalscorer as he led the side to their record fourth title.

His performances for Nigeria in the 2013 FIFA U-17 World Cup led to interest from clubs in Europe; teams following his progress included Arsenal,[15] Sporting CP and Porto.

He played in the FA Youth Cup final, where he scored, but ended on the losing side after Chelsea claimed a 5–2 aggregate victory.

[26] On 10 August 2015, Iheanacho was included in a first-team matchday squad for the first time in a competitive fixture, however he remained an unused substitute in their 3–0 win at West Bromwich Albion in their first game of the Premier League season.

[27] Nineteen days later, he made his competitive debut, replacing Raheem Sterling for the final minute of a 2–0 win against Watford at the City of Manchester Stadium.

[40] Four days later, Iheanacho came off the bench to score the final goal in City's 4–0 home win in the Champions League, against Borussia Mönchengladbach.

This list includes players such as Wayne Rooney, Ryan Giggs, Nicolas Anelka, Michael Owen and Romelu Lukaku.

[36][43] In October 2016, Iheanacho was nominated for the FIFA Golden Boy award, which was eventually won by Bayern Munich's midfielder Renato Sanches.

[46] Iheanacho was signed by Premier League club Leicester City on a five-year contract on 3 August 2017,[47] for a reported £25 million fee.

[53] A week later, Iheanacho netted a brace in Leicester's 3–1 win over Manchester United in the quarter-finals of the FA Cup, sending the club into the semi-finals of the competition for the first time since 1981–82.

[62] Iheanacho scored six goals in 26 matches in all competitions, as his club managed to achieve the EFL Championship, securing promotion back to the Premier League.

[63] On 31 July 2024, Iheanacho joined Spanish club Sevilla on a free transfer following the expiration of his contract at Leicester City.

[68] Iheanacho played a significant role in the 2013 FIFA U-17 World Cup, where he won the Golden Ball award for player of the tournament.

[73] Iheanacho made his senior debut as a substitute in a 2018 FIFA World Cup qualifying match against Eswatini in which Nigeria drew 0–0.

[78] Despite the change made in the coaching personnel in August 2016, he distinguished himself again as one of the most important players in the team when he scored two superb goals in the two matches against Tanzania in Uyo and Zambia in Ndola, during the AFCON and 2018 World Cup qualifications respectively.

[84] In the semi-final match against South Africa, Iheanacho, coming off the bench,[85] scored the winning penalty in a 4–2 victory during the shootouts following a 1–1 draw, which qualified his country to the final.

[98] His manager, Brendan Rodgers described him as an incredible, hardworking, and a highly talented player with no ego, in an interview with BBC and Sky Sports.

[103] Former British strikers and sports pundits, Gary Lineker and Alan Shearer, described him as “bag of talents” and a player who has a great pace and massive potentials.

[104] His manager, Craig Shakespeare proclaimed him as an enormously talented player that has shown a huge amount of promise at every level in which he’s played.

[107][108] Former English Ballon d'Or nominee and pundit Rio Ferdinand has described him, saying to Sports Extra; 'Kelechi at the moment is the best Nigerian player playing in the EPL this season, because he scores goals man, he’s a goalscorer'.

[110] He idolizes Kaka, Wayne Rooney, Didier Drogba and Leo Messi,[111][112] and has profiled Ronaldinho and Sergio Aguero as his inspirations,[113] also Jamie Vardy who has been described by pundits as his rival.

[116] He has also expressed his interest to emulate attacking midfielder Jay-Jay Okocha and forward Nwankwo Kanu in the Premier League and they have both cited Iheanacho as a great player and one of the best strikers in the world.