2021–22 Belgian First Division A

The 2021–22 Belgian Pro League (officially known as Jupiler Pro League due to sponsorship reasons) was the 119th season of top-flight football in Belgium. Club Brugge completed their first league Championship hat-trick since the 1970s by edging out long-time leaders Union Saint-Gilloise, who had led for 200 days until losing twice to Club in the title play-offs. Had Union achieved their unlikely success, they would have been the first newly promoted side to win the Belgian League, and the first to claim a top-20 ranked European league since FC Kaiserslautern's 1997–98 Bundesliga triumph in Germany.

On the final matchday of the previous season, Royal Excel Mouscron was overtaken by Waasland-Beveren, pushing them into a direct relegation spot and thus causing the Mouscron team to return to the second level after seven seasons. Waasland-Beveren would eventually face the same fate as a few weeks later they lost the Relegation play-off against Seraing, ending a span of nearly a decade at the top level.

The team from Seraing is a newcomer at the highest level, although a former team with the same name, R.F.C. Seraing (1904), last played at the top level 25 seasons ago and many supporters see the current Seraing as a continuation of the former. The place of Excel Mouscron was taken by 2020–21 Belgian First Division B champions and former Belgian giants Union Saint-Gilloise, returning to the top level after 48 years and already gained 11 Belgian Championship titles, mostly in the 1900s and 1930s.

Originally, as decided in 2020, the clubs agreed to reduce the number of teams again to 16 following the 2021–22 season, as due to the COVID-19 pandemic exceptionally no teams were relegated from the 2019–20 Belgian First Division A, which causing the league to temporarily expand to 18. This would mean that there would be three teams relegating from the 2021–22 Belgian First Division A with only one team promoted from the 2021–22 Belgian First Division B. However, on 14 June 2021, the clubs agreed to keep playing with 18 teams at the highest level up to (and including) the 2022–23 season, meaning that the 2021–22 Belgian First Division would continue the format of the previous season, with only one team relegating and the penultimate team playing a play-off match against the runner-up of the 2021–22 Belgian First Division B to avoid relegation. The title and Europa League playoffs remain shortened, with only the top four teams playing for the title and number 5 through 8 playing the Europa League playoffs. For the teams finishing in positions 9 through 16, the season ends immediately following the regular season. The request to keep playing with 18 teams at the highest level mainly came from the smaller teams which were already struggling following the financial impact of the COVID-19 pandemic. The bigger clubs agreed to continue the current format but demanded that U23 teams be permanently added to the lower leagues. As such, the intention is that from the 2022–23 season on, there will be 4 U23 teams playing added to each of the second, third and fourth level of Belgian football, with the final standings of the 2021–22 U23 league to determine which team will start at which level.

Returning to top-flight football after 48 years away, Union Saint-Gilloise earned a 3–1 opening-day win away to Brussels' traditional giants Anderlecht, Union hosted reigning champions Club Brugge on 1 August 2021 in their first home game in the top division since 1973, being edged out 1–0 through a late Eduard Sobol winner.

In a difficult January run against all of the previous season's top four, Union beat Anderlecht, Genk and Royal Antwerp, drawing 0–0 away to Club Brugge. By the end of the regular season, Union were top on 77 points, five ahead of Club Brugge, with Antwerp and Anderlecht also qualifying for the six rounds of play-offs, where the quartet would bring forward half of the regular season points into the play-offs. Hence, Union would resume on 39, Club 36, with Anderlecht and Antwerp both on 32.

Union started the play-offs strongly, beating Anderlecht 3–1 and thus becoming the first club ever to inflict three defeats on the Mauves in the same league season. A 0–0 draw away to Antwerp saw the lead over Club Brugge maintained at three points.

The title race swung in the direction of Bruges in back-to-back games between Union and Club, with the champions earning a tight 2–0 win in Brussels to draw level on points, with Club going top under the "half-points" rule, as Union had needed their tally from the regular season rounded-up. Club Brugge won the midweek return 1–0 at the Jan Breydel through an own goal from goalkeeper Anthony Moris to take a three-point lead with two games to go.

Club Brugge clinched the league crown in their next (and penultimate) game against Royal Antwerp, despite Union beating Anderlecht for the fourth time in the season 2–0 at Lotto Park. Eventually, Club finished four points clear of Union SG, 50 points compared to USG's 46, historically qualifying Union for the UEFA Champions League qualifiers. It was the completion of a three-in-a-row for Club Brugge, whose coach Alfred Schreuder would leave within 48 hours of the title success for Ajax.

Union had been top for 200 days.

League glory for Union would have seen them become the first newly promoted side to win a top-20 European national league championship at the first attempt since Kaiserslautern's 1998 Bundesliga success.

Union's runners-up spot qualified them for the UEFA Champions League qualifiers, sending them into European football for the first time since 1964–65, and their first UEFA competition after featuring in five editions of the Fairs Cup in the 1950s and 60s.

The table lists the positions of teams after completion of each round. However, several matches were not completed in the intended timeframe, resulting in the table below showing teams with different number of matches played as from matchday 19:

• The match between Standard Liège and Beerschot of matchday 19 was postponed due to a strike by the police. With the match being cancelled less than three hours prior to the match, Beerschot requested to be given a 0–3 win by forfeit; however the ruling was not in their favour.
• The match between Kortrijk and Antwerp of matchday 21 was postponed due to a large number of players of Antwerp testing positive for COVID-19 one day prior to the match. The match was played between matchdays 25 and 26.
• With Genk missing nine players in January 2022 due to the 2021 Africa Cup of Nations and the CONMEBOL 2022 FIFA World Cup qualifiers, the club was allowed to shift two of its matches. The match between Genk and Mechelen of matchday 24 was shifted forward and was played between matchdays 22 and 23, while the match between Oud-Heverlee Leuven and Genk of matchday 25 was moved backwards to be played between matchdays 26 and 27
• The match between Zulte Waregem and Oostende of matchday 22 was postponed due to a large number of players of Zulte Waregem testing positive for COVID-19 two days prior to the match.
• On 15 January 2022, KV Mechelen decided not to send a team to their away match at OH Leuven, as part of matchday 22. The club "wanted to make a statement", as their earlier request to have the match postponed was declined due to their third goalkeeper not being considered in the number of players testing positive, as he was still under the age of 21. Initially, the disciplinary committee ordered the match to be replayed, as it rules that the rule based on age was discriminatory and hence not legal, eventually however the Belgian Court for Sports Arbitration ruled in favour of OH Leuven on 9 March, awarding them a 5–0 forfeit win.
• Finally, the match between Standard Liège and Charleroi of matchday 17 was abandoned in minute 87 due to home supporter violence, while Charleroi was leading 0–3. Due to the combination of it being almost completed, Charleroi leading strongly and Standard supporters being the cause of the problem, main media outlets were reporting the result as final, already including three points for Charleroi Only on 13 January 2022 it was ruled that the match would not be finished or replayed and that the result would stand.

Points obtained during the regular season were halved (and rounded up) before the start of the playoff. Union SG started with 39 points, Club Brugge 36 points, Anderlecht and Antwerp 32 points each. As the points of Union SG and Antwerp were rounded up, in case of ties they would always be ranked below the team (or teams) they are tied with. The deciding factor after that would be finishing position in the regular season.

Points obtained during the regular season were halved (and rounded up) before the start of the playoff. Gent started with 31 points, Charleroi with 27 points, and both Mechelen and Genk with 26 points each. The points of Genk were rounded up, and hence in case of ties they will always be ranked below the team (or teams) they are tied with.

The winner of Play-Off II was originally scheduled to play the fourth-placed team of Play-Off I to determine which team would qualify for the second qualifying round of the 2022–23 UEFA Europa Conference League. However, since Gent won both the 2021–22 Belgian Cup (thus already qualifying for the 2022–23 UEFA Europa League) and Play-off II, the fourth-placed team of Play-Off I qualified automatically for the Europa Conference League and the European play-off was not contested.

The team finishing in 17th place competes in a two-legged match with the runner-up of the 2021–22 Belgian First Division B, with the aggregate winner to play in the 2022–23 Belgian First Division A, while the losing team will take part in the 2022–23 Belgian First Division B.

On 2 April 2021, following a draw away to Oostende, Seraing was certain of finishing 17th and forced to play the relegation play-off against a team from the Belgian First Division B. Seraing had won promotion last season by winning the 2020–21 Promotion-Relegation play-off and will now be looking to avoid going down again the same way. One day later in the 2021–22 Belgian First Division B, RWDM lost their match away to Deinze, meaning they would finish second and thus play Seraing for promotion.

Seraing won 1–0 on aggregate

Seraing remains in Belgian First Division A. RWD Molenbeek remains in Belgian First Division B.

As of 10 April 2022

The official statistics were calculated after the play-offs.