There is provided a sheet tray including: first, second and third trays. The second tray moves between a first position and a second position in which an overlapping area is smaller than that obtained in the first position. The third tray includes a third support surface and a fourth support surface. The third support surface includes a protrusion which protrudes upward to be positioned above the first support surface in a state that the third tray is in the first pivoting position. The third tray overlaps with the first support surface in a state that the second tray is in the first position and that at least a part, of the third tray, except for the protrusion is positioned below the first support surface, and the third tray does not overlap with the first support surface in a state that the second tray is in the second position.