The Belgian Pro League (Dutch: Eerste klasse; French: Championnat de Belgique de football; German: Pro League), officially the Jupiler Pro League (Dutch pronunciation: [ˈʑypilɛr ˈproː ˌlik]) for sponsor Jupiler, is a professional association football league in Belgium and the highest level of the Belgian football league system. Contested by 16 clubs from the 2023–24 season until 2025–26 when it will expand to 18 teams from 2026–27 onwards, it operates on a system of promotion and relegation with the Challenger Pro League.

Seasons run from late July to late March, with teams playing 30 matches each in the regular season, and then entering Play-offs I (also known as the Championship Playoff, title playoffs or Champions' play-offs), Play-offs II (also known as the Europa League playoff or Europe play-offs) or Play-offs III (also known as the Relegation play-offs) according to their position in the regular season. Play-offs I are contested by the top-six clubs in the regular season, with each club playing each other twice. The teams finishing in 15th and 16th place are relegated directly, however, the 14th place team plays a promotion-relegation play-off against the 3rd place team of the Challenger Pro League.

The competition was created in 1895 by the Royal Belgian Football Association and was first won by FC Liégeois. Of the 74 clubs to have competed in the first division since its creation, 16 have been crowned champions of Belgium. Anderlecht is the most successful league club with 34 titles, followed by Club Brugge (19), Union Saint-Gilloise (12) and Standard Liège (10). It is currently ranked 8th in the UEFA rankings of leagues based on performances in European competitions over the last five-years. The competition was ranked 3rd when the UEFA first published their ranking in 1979 and also the next year in 1980, which is the best ranking the Belgian First Division has ever achieved.

The first league in Belgian football was held in 1895–96 as a round-robin tournament with seven teams: Antwerp FC, FC Brugeois, FC Liégeois, RC de Bruxelles, Léopold Club de Bruxelles, SC de Bruxelles, and Union d'Ixelles. FC Liégeois became the first champion of Belgium. The first eight titles in Belgian football were all won by FC Liégeois or RC de Bruxelles. There was no promotion and relegation system at the time, but the last two finishers (FC Brugeois and Union d'Ixelles) withdrew and a new club entered the competition (Athletic and Running Club de Bruxelles). During the 1896–97 season, SC de Bruxelles withdrew, so the 1897–98 season was played by five clubs. In the seasons 1898–99 and 1899–1900, the football association introduced a new format with two leagues at the top level and a final game in two legs. The format changed back to one league with nine clubs in 1900–01, then again to two leagues from 1901–02 to 1903–04, this time with a final round among the top two teams of each league. In 1904–05, the championship was organised with one league of 11 teams. Athletic and Running Club de Bruxelles withdrew during the season and, from the 1906 season on, a system of promotion and relegation was introduced with the winner of the second division replacing the last-placed team of the first division. ^{[citation needed]}

In 1906–07, Union Saint-Gilloise won their fourth consecutive title as RC de Bruxelles had from 1899–1900 to 1902–03. Both clubs claimed the next three titles before CS Brugeois won their first title, finishing one point ahead their rival of FC Brugeois. At the end of the 1907–08 season, the number of teams in the first division was increased from 10 to 12 clubs, with Promotion champion RC de Gand and runner-up ESC Forest being promoted while no first division was relegated. As World War I approached, Daring Club de Bruxelles confirmed its status of challenger, even winning the title in 1911–12 and 1913–14. Only Union Saint-Gilloise could face them in that period, winning the 1912–13 championship with a better goal difference. Since 1911–12, two clubs are relegated each year to the Promotion and two clubs from the Promotion are promoted.

During World War I, the football championship was suspended. It resumed in 1919–20 with FC Brugeois claiming their first title after five second places, among which were two lost final games and one lost test-match. At the end of the 1920–21 season, the number of teams was increased from 12 to 14, with only Uccle Sport, the last-placed team of the first division, being relegated, and the first three teams from the Promotion being promoted (Standard Club Liégeois, FC Malinois, and RSC Anderlechtois). From 1921–22 to 1931–32, the decade was dominated by teams from the province of Antwerp: Beerschot AC, with Raymond Braine, won their first five titles, Antwerp FC their first two and the small club of Liersche SK (led by striker Bernard Voorhoof) won their first one in 1931–32. The challengers at the time were CS Brugeois (two titles in that period), Union Saint-Gilloise (one title), Daring Club de Bruxelles and Standard Club Liégeois. Starting 25 December 1932, Union Saint-Gilloise had a record 60 games unbeaten run in the championship (spanning three seasons), winning the 1932–33, 1933–34, and 1934–35 titles. The rival of Union during this period was Daring Club de Bruxelles. They claimed the next two championships. Following the come-back of player Raymond Braine to Beerschot, the Antwerp club won the last two titles before World War II. ^{[citation needed]}

On 10 May 1940, German troops invaded Belgium and the seasons 1939–40 and 1940–41 were suspended. The competition resumed in September 1941 and Liersche SK won their second title. At the end of the season, no club was relegated and the number of clubs was increased from 14 to 16. The next season, Liersche SK lost three key players (two of them in a bomb attack and the other one due to a heavy injury sustained on the pitch) and they ended at 3rd place while the neighbours of KV Mechelen became champion for the first time in their history. In 1943–44, Antwerp FC won the title. The league was suspended again in 1944–45 because of World War II.

The league resumed play in 1945–46 with a title for KV Mechelen. At the start of that season, the First Division went from 16 to 19 clubs, with three clubs promoted from the First Division and no team being relegated. The top scorer award was also introduced that season, won by Bert De Cleyn from KV Mechelen. Two seasons later, five clubs were relegated and two promoted. In 1946–47, RSC Anderlechtois won their first championship with Jef Mermans as the key striker and they dominated the Belgian football over the next 9 years with 6 more titles, with KV Mechelen (in 1947–48) and FC Liégeois (in 1951–52 and 1952–53) claiming the remaining titles. The Belgian Golden Shoe award was introduced in 1954, rewarding the best player in the first division for the past calendar year, thus over two half seasons. ^{[citation needed]}