The 1999 Football League Second Division play-off final was an association football match which was played on 30 May 1999 at Wembley Stadium, London, between Manchester City and Gillingham. The match was to determine the third and final team to gain promotion from the Football League Second Division, the third tier of English football, to the First Division. The top two teams of the 1998–99 Football League Second Division season gained automatic promotion to the First Division, while the clubs placed from third to sixth in the table took part in play-offs. Manchester City ended the season in third position while Gillingham were fourth. The winners of these semi-finals competed for the final place in the First Division for the 1999–2000 season. In the semi-finals, Gillingham defeated Preston North End and Manchester City beat Wigan Athletic.

It was Gillingham's first match at Wembley Stadium, although Manchester City had played there on eleven previous occasions. The final drew a crowd of just under 77,000, the largest crowd to ever witness a Gillingham match, and was refereed by Mark Halsey. The match was scoreless until the 81st minute, when Carl Asaba gave Gillingham the lead. Robert Taylor added a second goal five minutes later. Kevin Horlock scored for City in the 90th minute to halve the deficit and, in the fifth minute of injury time, Paul Dickov scored an equaliser to make the score 2–2 and send the game into extra time. With no further goals being scored, the match was decided by a penalty shoot-out, which City won 3–1 to gain promotion.

Manchester City's next season saw them secure automatic promotion to the FA Premier League after ending their campaign as runners-up. Gillingham finished their following season in third place in the Second Division and qualified for the play-offs again, where they secured promotion to the First Division with a 3–2 victory against Wigan Athletic in the final.

The teams finishing in the top two positions in the Second Division, the third tier of the English football league system, in the 1998–99 Football League season gained automatic promotion to the First Division. The teams finishing between third and sixth inclusive competed in the play-offs for the third and final promotion place. Manchester City finished the regular season in third place, two points ahead of fourth-placed Gillingham. Both therefore missed out on the two automatic places for promotion to the First Division and instead took part in the play-offs, along with Preston North End and Wigan Athletic, to determine the third promoted team. Manchester City finished five points behind Walsall (who were promoted in second place) and nineteen behind league winners Fulham.

Gillingham's opponents for their play-off semi-final were Preston North End, with the first match of the two-legged tie taking place at Deepdale in Preston on 16 May 1999. After a goalless first half, David Eyres put Preston ahead in the 54th minute. Robert Taylor equalised with 11 minutes to go and the match ended 1–1. The second leg was held three days later at Priestfield Stadium in Gillingham. Within two minutes of the start of the match, Gillingham took the lead through Andy Hessenthaler: Barry Ashby passed to Carl Asaba who guided the ball to Hessenthaler to score. Gillingham dominated the remainder of the half and, despite pressure from Preston after the interval, they held onto their lead; Vince Bartram, the Gillingham goalkeeper, dived full-length across his goal to keep out a strike from Jon Macken. The match ended 1–0 and Gillingham progressed to the final with a 2–1 aggregate victory.

Manchester City faced Wigan Athletic in their semi-final and the first leg was played at Springfield Park in Wigan on 15 May 1999. Within 20 seconds, the home side had taken the lead: a misunderstanding between Manchester City goalkeeper Nicky Weaver and his team-mate Gerard Wiekens allowed Stuart Barlow to score from 15 yards (14 m). Paul Dickov equalised with 13 minutes of the match remaining and the game ended 1–1. The second leg took place four days later at Maine Road in Manchester. City dominated the early stages and took the lead in the 27th minute through Shaun Goater, who put the ball past Roy Carroll in the Wigan goal with his chest from a Michael Brown cross. With four minutes remaining, a shot by Wigan's Graeme Jones struck the crossbar. The match ended 1–0 and Manchester City progressed to the final 2–1 on aggregate.

The match was Gillingham's first appearance at Wembley Stadium, the country's national stadium and the venue reserved for major tournament finals since 1923. Manchester City, by comparison, had played there on eleven previous occasions in FA Cup and League Cup finals. Gillingham were aiming to reach the second tier of English football for the first time in their history, whereas their opponents had spent more than 100 seasons in the top two tiers and had played in the top-level FA Premier League as recently as the 1995–96 season. At the end of the 1997–98 season, City had been relegated to the third tier of English football for the first time.

This season saw the first competitive matches between the sides: the first game, at Maine Road in November 1998, ended in a goalless draw while the return match played at Priestfield the following April ended in a 2–0 victory for Manchester City. Asaba was the season's top scorer for Gillingham with 22 goals (20 in the league and 2 in the Football League Trophy) followed by Taylor, who scored 19 goals in the regular season (16 in the league and 3 in the Football League Trophy). Manchester City's Goater was leading scorer for his side, with 20 goals (17 in the league, 1 in the FA Cup and 2 in the League Cup) followed by Dickov on 13 (10 in the league, 1 in the FA Cup and 2 in the League Cup) and Kevin Horlock with 10 (all in the league).