The club was founded on April 25, 1926, and is affiliated to the Royal Belgian Football Association with base number 1124.

In the 1983/84 season, however, there was already a first major success, in the Belgian Cup, by beating first division side Beerschot op het Kiel 0–4 in the 32nd finals, with Lucien Olieslagers as coach.

In the 16th finals, the cup adventure then ended for De Leeuwen, after losing 2–1 at Het Lisp, against Lierse.

Led by Eddy Lodewijckx and with Roger Kemland as the club's first manager, De Leeuwen became champions with six points more than the second in the ranking: Heist Sportief.

After the previous big cup success in 1983, Zwarte Leeuw overcame consecutively Berchem Sport, Racing Genk and Antwerp (in two matches) in 1989.

In the final round, which would determine whether or not they would advance to the First Division, the club faced Boom, Racing Genk and Lommel.

This day is still the highlight of the club's history until now, never was Zwarte Leeuw closer to the highest division of Belgian football.

The objective was to prevent the free fall, make Zwarte Leeuw financially healthy and stable again and preferably also return to the Third Division.

Zwarte Leeuw did not play a significant role in the Fourth Division from then on, with the exception of the good 2005/06 season.

After successively defeating Zandvliet, Londerzeel, Lyra, Sint-Gillis-Waas and Sint-Niklaas, the club drew KAA Gent in the 16th finals.

After financial troubles (past debts and problems with taxes), Zwarte Leeuw still played champion in the First Provincial Division, with five points more than the second in the ranking, Antonia.

That last fourth-place finish ensured that in the 2016/17 season, under the leadership of Gert Jochems, Zwarte Leeuw was classified in the Second Amateur Division after the league reform.

After two seasons, however, Zwarte Leeuw did disappear from that Second Amateur Division after losing the final round in a 2018 match against Pepingen-Halle.