Série 9100 were a class of metre gauge diesel railcars built for use by the Portuguese Railways (CP) on the Tâmega line. Only three were built; they were constructed in Sweden by NOHAB in 1949. They were essentially a narrow gauge version of CP's larger Série 0100 railcars.
They were withdrawn from service in 2002 and replaced by Série 9500 railcars.
The Tâmega line closed in 2009.