Embodiments of the present disclosure provide a thin film transistor assembly, an array substrate and a display panel. The thin film transistor assembly includes a first thin film transistor and a second thin film transistor disposed on a substrate. The first thin film transistor includes a first source electrode, a first drain electrode, and a first active layer. The second thin film transistor includes a second source electrode. The first source electrode is disposed on a side of the first active layer facing towards the substrate. The first drain electrode is disposed on a side of the first active layer facing away from the substrate. An orthogonal projection of the first source electrode on the substrate overlaps an orthogonal projection of the second source electrode on the substrate.