This is a list of bus routes operated by the Washington Metropolitan Area Transit Authority (WMATA), branded as Metrobus. Many are the descendants of streetcar lines operated by the Capital Transit Company or its predecessors.
The list of Metrobus routes has been split by region:
As a part of the BetterBus system improvement plan, the Washington Metropolitan Area Transit Authority (WMATA) created new routes under a new route naming convention based on the locations the buses primarily serve and their service type:
If a bus is running a limited-stop (i.e. "express") service, it is denoted by the final letter X.
From 1973 until June 29, 2025, Metrobus routes followed the rules below:
Odd-numbered routes are typically part-time variants of even-numbered routes. At one time, odd numbered routes were express routes, but that distinction has been abandoned. Most Maryland and Washington, D.C., routes are grouped by their first digit. When this system was laid out in 1936, the following clustering was used: