An organic light emitting display apparatus including a substrate, an organic light emitting portion comprising a plurality of organic light emitting devices formed on the substrate, and an encapsulation portion for encapsulating the organic light emitting portion. The encapsulation portion includes a porous layer formed on the organic light emitting portion, a planarization layer formed on the porous layer, and a barrier layer formed on the planarization layer. The porous layer prevents impurities from being concentrated at a part of the porous layer.