A luminaire includes a body including a lighting compartment and a bezel rim around at least a portion of a perimeter of the body. The luminaire also includes clamping plates that extend a length of the luminaire. As the clamping plates are secured in a lighting compartment of the luminaire, they provide a clamping force to secure an LED circuit board in the lighting compartment. A base of the lighting compartment may also serve as a heatsink for the LED circuit board. A low-profile luminaire according to such features is also provided.