The tram route 51 in Brussels, Belgium, is a tram route operated by STIB/MIVB, which connects Heysel/Heizel metro station in the City of Brussels to the Van Haelen stop in the municipality of Uccle.

Past Jette Cemetery, routes 19 and 51 separate, with route 51 heading towards Belgica metro station via the Avenue Charles Woeste/Charles Woestelaan, and then towards Ribaucourt metro station via the Boulevard Belgica/Belgicalaan and the Boulevard du Jubilé/Jubelfeestlaan.

At Ribaucourt, the route joins the Small Ring (Brussels' inner ring road) at the Place Sainctelette/Saincteletteplein via the Boulevard Léopold II/Leopold II-laan, crosses the Brussels Canal, connects with the Metro at Yser/IJzer, enters the Pentagon (Brussels' city centre), then runs alongside the canal up to the Ninove Gate.

When exiting the tunnel, route 51 heads towards the Place de l'Altitude Cent/Hoogte Honderdplein, then joins the Chaussée d'Alsemberg/Alsembergsesteenweg up to Uccle-Calevoet railway station, then joins again the Chaussée d'Alsemberg via the Rue d'Angleterre/Engelandstraat and the Rue du Château d'Or/Gulden Kasteelstraat.

This is due to construction work at Albert station which will make it inaccessible to route 51.