During the 1986–87 English football season, Gillingham F.C. competed in the Football League Third Division. It was the 55th season in which the club competed in the Football League, and the 37th since the club was voted back into the league in 1950. Gillingham began the season strongly and were top of the Third Division table shortly before the mid-point of the season. The team's form declined in the second half of the season; to qualify for the play-offs for promotion to the Football League Second Division, the team needed to win their final game and both Bristol City and Notts County had to fail to win theirs. A victory over Bolton Wanderers, combined with both the other teams being held to draws, meant that Gillingham finished in fifth place and qualified for the play-offs. After beating Sunderland in the semi-finals, Gillingham faced Swindon Town in the final. The two teams drew 2–2 on aggregate, necessitating a replay at a neutral venue, which Swindon won 2–0 to claim a place in the Second Division.
During the season, Gillingham also reached the third round of the FA Cup, the second round of the Football League Cup, and the southern section semi-finals of the Associate Members' Cup. The team played 63 competitive matches, winning 31, drawing 12 (including one decided by a penalty shoot-out), and losing 20. Tony Cascarino was the club's leading goalscorer, with 30 goals in all competitions. Howard Pritchard and Paul Haylock made the most appearances; both played in 62 of the club's 63 matches. The highest attendance recorded at the club's home ground, Priestfield Stadium, was 16,775, for the home leg of the play-off final.
Background and pre-season
The 1986–87 season was Gillingham's 55th season playing in the Football League and the 37th since the club was elected back into the League in 1950 after being voted out in 1938. It was the club's 13th consecutive season in the Football League Third Division, the third tier of the English football league system, since the team gained promotion from the Fourth Division as runners-up in 1974. In the 12 seasons since then, the team had achieved a best finish of fourth place, one position away from promotion to the Second Division, a feat achieved in both the 1978–79 and 1984–85 seasons. The club had never reached the second level of English football in its history. In the 1985–86 season, Gillingham had finished fifth and missed out on promotion by two places.
Keith Peacock was the club's manager for a sixth season, having been appointed in July 1981. Paul Taylor served as assistant manager, Bill Collins, who had been with the club in a variety of roles since the early 1960s, held the post of first-team trainer, and John Gorman managed the youth team. Mark Weatherly took over as team captain, replacing Keith Oakes, who was only named as a substitute for the opening game of the season and left the club soon afterwards to join Fulham. Before the season began, a series of disputes took place involving the club's board of directors. In late June, chairman Charles Cox announced that he had dismissed three directors from their posts; the following day, the ousted trio gave an interview to the press and claimed that under his chairmanship the club's debt had reached £700,000 and that it faced the threat of a potential liquidation order from the Inland Revenue. Four days later, following a showdown meeting between the two parties, Cox resigned as chairman and the three deposed directors returned to the board with one of them, Roy Wood, becoming the new chairman. The directors then issued a statement to Gillingham supporters stating that the club's finances were under control and that money would be available to manager Peacock to sign new players in anticipation of another challenge for promotion. In July, the club's financial director announced that a settlement had been reached with the Inland Revenue.