[5] Filbert Street was gradually upgraded during the 20th century and with the advent of the Taylor Report in January 1990 requiring all clubs in the top two divisions to have all-seater stadiums by August 1994, Leicester City's directors began to investigate building a new stadium during the early 1990s, but decided to take the redevelopment option by building a new stand on one side of Filbert Street and fitting seats into the remaining standing areas, giving the stadium a 21,500 all-seated capacity by the 1994–95 season.

Filbert Street's conversion to an all-seater stadium coincided with their promotion to the Premier League after a seven-year exile from the top flight, and with their relegation after just one season it appeared the 21,500 capacity would be adequate.

However, success in the late 1990s saw crowds rise, which meant virtually every game at Filbert Street was a sell-out by the end of the decade.

In early 1998, plans were announced for a 40,000 all-seater stadium to be built at Bede Island South in time for the 2000–01 season, but they were abandoned on 5 January 2000.

[6] The relocation option was soon settled upon, as plans were unveiled on 2 November 2000 for a 32,000-seat stadium in the Freeman's Wharf area, situated alongside the River Soar.

After becoming official contractors, Martin Peat, managing director of Birse Building said: "We are delighted to have been selected by Leicester City Football Club as construction partners for their new stadium which, when completed, will be one of the finest in Europe."

"[9] At the time of building, two large dual-purpose concourses, which could be used as exhibition centres on non-matchdays, were a first in British stadium design.

Manager Micky Adams described the stadium in the club's pre-match programme: “I am sure everyone will agree our new home is pretty special.

[11] As part of the deal which brought the club out of receivership, the stadium's ownership reverted to American academic retirement fund TIAA–CREF, who had supplied £28 million via a bond scheme towards the stadium's construction, with the club taking a long-term lease while the bond repayments were made.

[16] On 28 July 2021, Leicester City confirmed that they would reveal plans to the public which included increasing the capacity to 40,000, as well as several development projects in the area surrounding the stadium.

[17] The club announced on 25 October 2021, that they had submitted a hybrid planning application to Leicester City Council for the redevelopment of King Power Stadium and the surrounding area.

[21] On 27 October 2018, a Leonardo AW169 helicopter carrying club chairman Vichai Srivaddhanaprabha and four others crashed in a car park outside the stadium.

The agreement for naming rights was superseded halfway through the ten-year period, in May 2007, when Walkers again paid a seven-figure sum to extend their sponsorship of the stadium until 2017.

Since opening in 2002, the stands inside the stadium have had various names but are currently titled the North, East, South (Spion Kop) and West respectively.

During their absence from Wembley, the England national football team played a home friendly game against Serbia and Montenegro at the stadium on 3 June 2003.

On 12 October of the same year, the ground hosted an international friendly match between Brazil and Jamaica, with Roberto Carlos scoring the winner.

[35] On 21 September 2014, Leicester went on to produce one of the greatest comebacks in Premier League history, as they won 5-3 against Manchester United at King Power Stadium.

[37] On 7 May 2016, Leicester City lifted the 2015–16 Premier League trophy following a 3–1 win versus Everton, less than a week after officially becoming champions as Tottenham Hotspur failed to beat Chelsea.

[43] On 4 May 2024, the club lifted their record eighth second-tier title at home to Blackburn Rovers, as a result of winning the 2023–24 EFL Championship.

The first three were either to capitalise on the larger capacity with the greater interest in high-profile games, or when competition rules demanded the match be played away from their normal home ground.

The stadium has hosted international rugby, including a match between a World XV and South Africa on 3 December 2006 to mark the centenary of the Springboks' first game abroad.

This rugby match took place prior to seats being removed to provide segregation of rival football fans, reducing the capacity of the ground from exactly 32,500 to 32,261.