[8] During that season, King scored eight goals in 21 appearances for the Leicester academy side, which saw them win the FA Premier League Group B.

[10] He also went on trial with Conference National team York City in August,[9] and after playing in a pre-season friendly against Sheffield he turned down a possible loan move to the club on the advice of his agent.

[11] King made his first team debut in a 0–0 draw with Wolverhampton Wanderers on 2 October 2007,[12] before scoring his first senior goal with a 35-yard shot described as a "rocket" in a 2–1 defeat to Southampton on 1 December.

[16] King dedicated his award to team captain Stephen Clemence, who missed the entire season through injury.

[19] Following a fine start to the 2009–10 season, King said on 23 November there is a firm belief that the team can win promotion to the Premier League.

[20] He drew praise from then-manager Nigel Pearson after scoring his fourth goal of the season in a 2–1 FA Cup win over Swansea City on 2 January 2010.

[24] Three days later, King's form that season was acknowledged by his fellow professionals as he was named in the Championship's PFA Team of the Year with teammate Kyle Naughton.

King regained his form at the beginning of the following season though, scoring a goal in both the opening 2012–13 Championship fixtures against Peterborough United and Charlton Athletic respectively.

King started the 2013–14 Championship season how he finished the last: Scoring twice in the first 8 games, both fantastic strikes against Birmingham City and Blackpool.

King made his Premier League debut, playing the full 90 minutes in the 2–2, opening day draw with Everton, putting in an impressive display, finishing the match with a 95.6% pass completion record.

[34] King started the new campaign in the Leicester team, playing the full 90 minutes as Leicester topped the Premier League table following a 4–2 win against Sunderland at the King Power Stadium on 8 August 2015, with new manager Claudio Ranieri singling out him and midfield partner Danny Drinkwater for praise.

Andy King became the fourth Welsh footballer to win the Premier League, after Ryan Giggs, Mark Hughes and Clayton Blackmore.

[40] He scored his second goal of the season against Derby County in the FA Cup, captaining Leicester City to a 3–1 home win.

[45] On 6 January 2019, King played for the first time of the season for Leicester in the FA Cup defeat against League Two side Newport County.

He was given a straight red card in the 47th minute on 13 October 2014, in a home qualifier against Cyprus, for a foul on Constantinos Makrides.

[67] Manager Chris Coleman blamed the attitude of himself and his staff for aggressively rallying the team prior to King's red card.

[70] On 2 September 2017, King came on as a half time substitute to help Wales to a 1–0 victory against Austria in a 2018 FIFA World Cup qualifier.