The 1986–87 season marked a significant chapter in the history of Gillingham F.C., as the club participated in the Football League Third Division. This season was particularly noteworthy because it marked the 55th year Gillingham competed in the Football League since its formation, and the 37th year since the club was re-elected to the league after a brief hiatus in 1950. The season commenced with Gillingham displaying impressive form, managing to secure the top position in the Third Division standings just prior to the midpoint of the season.
However, as the season progressed, the club's performance entered a decline in the latter half, diminishing their hopes for direct promotion. To qualify for the play-offs, which would offer a chance to ascend to the Football League Second Division, Gillingham found themselves in a situation where they had to win their final game against Bolton Wanderers. Concurrently, both Bristol City and Notts County needed to fail to secure victories in their matches.
In a thrilling conclusion to the regular season, Gillingham succeeded in winning against Bolton, which was critical as it allowed them to edge into fifth place in the league table. The outcomes of the other matches fell in favor of Gillingham, as both Bristol City and Notts County were unable to claim victories, ultimately entitling Gillingham to compete in the play-offs.
Gillingham’s journey through the play-offs saw them face Sunderland in the semi-finals, where they managed to secure a spot in the final after overcoming their opponents. The final matchup was against Swindon Town, resulting in a tense and exhilarating match. The two teams concluded the first leg with a 2–2 aggregate score, prompting a replay at a neutral location to determine which club would advance to the Second Division.
In the replay, however, Swindon Town emerged victorious with a score of 2–0, thereby claiming their position in the Second Division while Gillingham's ambitions for promotion were thwarted. This season exemplified both the highs and lows of competitive football, highlighting the unpredictability and the significance of crucial matches that can alter a team's trajectory.