An LED floodlight fixture includes (1) a housing that has (a) at least one end-portion and (b) a single-piece extrusion including (i) a base having an LED-adjacent surface and an opposite surface and (ii) a heat-dissipating section having heat-dissipating surfaces extending from the opposite surface, and (2) an LED arrangement mounted to the LED-adjacent surface in non-water/air-tight condition with respect to the housing. The housing preferably forms at least one venting gap to provide cool-air ingress to and along the heat-dissipating surfaces by upward flow of heated air therefrom. Additionally and/or alternatively, the base of the single-piece extrusion has one or more venting apertures to provide cool-air ingress for such purpose. One aspect of the invention involves the heat-dissipating section of the extrusion including a closed extruded wireway therealong enclosing wires extending to/from electrical component(s).