A light-emitting diode (LED) lighting fixture is provided as a potential solid state lighting (SSL) replacement fixture for a conventional HID lamp fixture. The LED lighting fixture includes a main housing having a bottom surface supporting an array of LEDs, a top surface and sides, and at least one driver provided in a side housing attached to a side of the main housing to drive the LED array. The thickness of the side housing is equal to or greater than the thickness of the main housing. A plurality of heat spreading fins is arranged on the top surface of the main housing.