The invention provides an OLED display panel and a display device. A retaining wall of the OLED display panel comprises a substrate retaining wall layer, an inorganic retaining wall layer and an organic retaining wall layer which are stacked, an inorganic retaining wall film and the cross section of the substrate retaining wall layer form an undercut shape, and the substrate retaining wall layer comprises a second flexible substrate. The inorganic retaining wall layer comprises an inorganic layer in the driving circuit layer, and the organic retaining wall layer comprises at least one of a planarization layer, a pixel definition layer and a supporting column. Based on the retaining wall structure, the retaining wall height is increased, the organic materials can be better prevented from flowing, and the distance between the retaining wall and the display area is reduced. Meanwhile, the undercut shape between the retaining wall and the display area can also increase the flow path of theorganic materials, so that the distance between the retaining wall and the display area can be further reduced. Moreover, the cutting cracks can be prevented from extending to the display area alongthe inorganic layer and the substrate, so that the size of a frame can be further reduced to a greater extent.