The first electric tramline in Porto was opened in 1895. Until 1946 the network was operated by the CCFP: Companhia Carris de Ferro do Porto. This was a private company. In 1946 the operations were taken over by the municipal owned STCP: Serviço de Transportes Colectivos do Porto (now Sociedade de Transportes Colectivos do Porto)

On this page an overview of the network development with maps for the CCFP and STCP periods.