Dennis Trident 2 (marketed as Dennis Trident, but once known as TransBus Trident 2/TransBus Trident) is a 2-axle low-floor double-decker bus chassis originally built by Dennis in the United Kingdom, which was unveiled in 1997 and replaced the Dennis Arrow. It was built by TransBus after Dennis was incorporated into the group in 2001 (the Dennis brand name was once dropped). From 2004, it was built by Alexander Dennis.
The Trident 2 chassis features a transversely mounted engine, with the radiator mounted on the left side of the engine compartment. It could be fitted with Cummins C-series Euro II engine (later Cummins ISCe Euro III engine), coupled to Voith or ZF gearbox. Trident 2 was available with Alexander ALX400, Plaxton President and East Lancs Lolyne/Myllennium Lolyne bodywork.
In the first few years of production, Trident 2 was popular in the United Kingdom, with a large number sold to large bus operators such as Stagecoach, First Group, Travel West Midlands and Lothian Buses. Some of the Tridents were exported to Ireland (for Dublin Bus ) and Spain (for sightseeing operations in Barcelona and Madrid). But later, due to increased competition after the launch of Scania OmniDekka and TransBus being put into administration, the sales of Trident 2 dropped significantly, leaving Stagecoach as its major buyer.
In 2005, Alexander Dennis unveiled a modified chassis, which was developed from the Trident 2 chassis, for its Enviro400. This chassis received a number of modifications such as longer front overhang and a different shape of fuel tank.