A combination of two formerly-separate companies, Ferrocarril Metropolità de Barcelona, SA.

The bus network serves Barcelona and the metropolitan area through 109 lines that cover a total distance of 920.62 kilometres.

In 2016, TMB carried 578.75 million passengers and had 7,744 employees.

[1] There is also an authority in Barcelona that seeks to coordinate and integrate other public transport companies (such as TRAMMET, for the local trams) into the same network, Autoritat del Transport Metropolità.

TMB changed its logo in 2014 after introducing a stencil-style variant of Helvetica for their publicity.