An LED light fixture includes a heat sink structure, at least one LED board in thermal engagement with the heat sink structure, the at least one LED board having at least one LED emitter thereon, and an on-board connector on the LED board for connecting electrical wiring to the LED emitter(s). At least one enclosing member forms with the heat sink an interior space enclosing a corresponding LED board, the rigid enclosing member defining a wiring aperture therethrough in alignment with the on-board connector. The LED light fixture also has an exterior wireway structure including a one-piece duct which has an end portion engaged with the wiring aperture and forms a channel for wires to the on-board connector. The wireway structure further includes a single-piece rigid cover secured with respect to the enclosing member and enclosing the duct.