This paper reports a mechanically flexible, transparent thin film transistor that uses graphene as a conducting electrode and single-walled carbon nanotubes (SWNTs) as a semiconducting channel. These SWNTs and graphene films were printed on flexible plastic substrates using a printing method. The resulting devices exhibited a mobility of ∼ 2 cm(2) V(-1) s -1), On/Off ratio of ∼ 10(2), transmittance of ∼ 81% and excellent mechanical bendability.