The present disclosure provides a backlight module and a display device, and relates to the field of display technology. The backlight module includes a light guide plate, a light source, a frame portion adjacent to a light incident surface of the light guide plate, and one or more positioning members for defining a position of the light source. The at least one positioning member includes a first positioning portion and a second positioning portion. The first positioning portion is located on a surface of the frame portion adjacent to the light incident surface. The second positioning portion is located on the light incident surface. The second positioning portion and the first positioning portion are mutually constrained to restrict relative movement of the light guide plate and the frame portion in a length direction of the light incident surface.