Modular lighting fixtures that allow convenient installation and removal of LED-based light-generating modules and controller modules. In one example, a modular lighting fixture includes a housing configured to be recessed into or disposed behind an architectural surface such as ceiling, wall, or soffit, in new or existing construction scenarios. The fixture housing includes a socket configured to facilitate one or more of a mechanical, electrical and thermal coupling of the light-generating module to the fixture housing. The ability to easily engage and disengage the LED-based light-generating module with the socket, without removing the fixture housing itself, allows for straightforward replacement of the light-generating module upon failure, or exchange with another module having different light-generating characteristics. Modular lighting controllers for such fixtures also may be easily installed in or removed from the fixture housing via the same access route by which the light-generating module is installed and removed.