An organic light-emitting display apparatus and a manufacturing method thereof have improved process stability and reliability by reducing damage to the organic light-emitting display apparatus during a manufacturing process. The organic light-emitting display apparatus includes: a substrate, a plurality of pixel electrodes, a pixel defining film, a plurality of hole control layers respectively arranged on the pixel electrodes, a plurality of emission layers respectively arranged on the hole control layers, a plurality of buffer layers respectively arranged on the emission layers, each of the buffer layers having a highest occupied molecular orbital (HOMO) energy level greater than the HOMO energy level of each of the plurality of emission layers, and an opposite electrode integrally provided over the buffer layers.