The invention relates to an outdoor lighting unit for lighting streets, pavements, industrial grounds, and the like, comprising one LED light source (11) which includes several light emitting diodes (21) in a two-dimensional array, and a housing (13). The housing has a single-piece solid housing element (15), which has at least one planar assembly section (31) on an underside, on which a backside of the LED light source is arranged in heat-conducting connection in a planar manner. The housing element further has on said underside a circumferential wall section (33), which projects downwardly from the plane of the assembly section. Further, the housing element comprises an exposed cooling section (37) on an upper side, which is convexly curved and has several cooling channels (39), which extend along the convex curvature. The housing element also comprises a holding portion (41), by means of which the lighting unit can be secured to a holding device (45) in a self-supporting manner.