The NMBS/SNCB Class 77 (also known as HLD 77 or HLR 77) is a class of 4 axle B'B' road switcher diesel hydraulic locomotive designed for shunting and freight work manufactured at the beginning of the 2000s by Vossloh Schienentechnik/Vossloh Locomotives at the Maschinenbau Kiel plant in Kiel, Germany for the National Railway Company of Belgium (SNCB/NMBS).

The initial order for 90 locomotives was given to Siemens in 1997 to replace an aging diesel fleet; the railway opted for a locomotive suitable for both shunting and mainline use, rather than separate classes.

[1] The locomotive is an off-centre cab design with a two-speed Voith hydraulic transmission driving all axles via cardan shafts.

[2] Auxiliary electrical supply is provided by an engine mounted alternator.

[8] Due to its relatively low power the locomotives work in multiple on heavy freight trains.