The 20 km de Bruxelles is a 20-kilometer race through Brussels, run every year on the last Sunday of May since 1980. In Belgian national or European election years, it moves one week earlier so it does not clash with compulsory voting. It starts at Parc du Cinquantenaire and draws a huge field, with runners sent off in successive waves and walkers given their own start. The event is big enough to feel like a city day out rather than a standard road race: recent fields have reached tens of thousands, with participants from more than 140 nationalities.
The route uses the streets of the Brussels-Capital Region and links many of the city’s major monuments, so runners get a broad tour of the capital rather than a closed park loop. Elite athletes, club runners, federal civil servants, charity teams, recreational runners, and walkers all share the event. Fanfares have been placed along the course since the early editions, and the race has steadily added practical touches such as clearer kilometer signs, more first-aid points, wristbands, bottled water, chip timing, and online registration. Its history also has a few very Brussels moments: one anniversary course was reversed because of construction, another edition nearly disappeared because of roadworks, and one shortened route followed the closure of Bois de la Cambre.