A thin film transistor that does not deform or exfoliate due to thermal or mechanical stress, a flat panel display having the same, and a method manufacturing the same, the thin film transistor including a substrate, a patterned buffer layer disposed on the substrate, a patterned active layer disposed on the buffer layer, a gate electrode insulated from the active layer, and a source electrode and a drain electrode that contact the active layer and are insulated from the gate electrode.