A thin film transistor array substrate includes: a base substrate; a first transistor including a first electrode on a surface of the base substrate, a spacer, on the first electrode, a second electrode on the spacer, a first active layer contacting the first electrode, the spacer and the second electrode, and a first gate electrode opposite to the first active layer with a first insulating layer interposed therebetween; a storage capacitor including a first storage electrode integrally connected to the first electrode or the second electrode, and a second storage electrode opposite to the first storage electrode with the first insulating layer interposed therebetween, where the second storage electrode is integrally connected to the first gate electrode; and a second transistor electrically connected to the storage capacitor, where the second transistor includes a second active layer extending in a direction intersecting the base substrate.