The 73 is a bus route that operates between Hengrove Depot and UWE Frenchay in Bristol.

On 1 February 2009, parts of the route that served the Ministry of Defence Abbey Wood facility, Filton High School, and a peak-hours only loop around Aztec West were all withdrawn in order to reduce journey times.

[8][9][10] In July 2020, biomethane powered Alexander Dennis Enviro400 City CBG buses were introduced on the route.

[14][15][16][17] From 22 January 2023, the northern section between Bradley Stoke and Cribbs Causeway was withdrawn following the introduction of the MetroBus route m4.

In September 2024, the route was again significantly altered, now being extended in the south to reach Hengrove Depot, and in the north it has been diverted to UWE Frenchay, having swapped the north end of its route with the 74 as part of major service changes enacted by First.