An OLED display panel and an OLED display device are disclosed. In the OLED display panel, a ratio of a width of a side of a first pixel opening adjacent to a pixel electrode layer to a length of a lateral surface of the first pixel opening is greater than a ratio of a width of a side of a second pixel opening adjacent to the pixel electrode layer to a length of a lateral surface of the second pixel opening, such that the nonuniform brightness between a first display area and a second display area is improved or even eliminated.