A dimmable outdoor lighting fixture apparatus, comprising: a luminaire fixture assembly comprising: a fixture housing, at least one light source supported in the fixture housing, at least one ballast or driver supported in the fixture housing and electrically coupled to provide power to the light source, and a 3-terminal twist-lock receptacle mounted to the fixture housing and operative to receive a twist-lock connector; a controller module, comprising: a twist-lock type connector operatively coupled to the twist-lock receptacle and providing three class 1 electrical connections (118a-c) between the controller module and the fixture assembly, a dimming component operative to selectively provide at least one dimming control value to the ballast or driver through the twist-lock receptacle to cause the ballast or driver to provide dimmable output from the light source; and a photo sensor operative to sense ambient light proximate the fixture assembly and to provide a sensed light signal or value to the dimming component, and where the dimming component is operative to selectively provide the dimming control value based at least in part on the sensed light signal or value. a luminaire fixture assembly comprising: a fixture housing, at least one light source supported in the fixture housing, at least one ballast or driver supported in the fixture housing and electrically coupled to provide power to the light source, and a 3-terminal twist-lock receptacle mounted to the fixture housing and operative to receive a twist-lock connector; a controller module, comprising: a twist-lock type connector operatively coupled to the twist-lock receptacle and providing three class 1 electrical connections (118a-c) between the controller module and the fixture assembly, a dimming component operative to selectively provide at least one dimming control value to the ballast or driver through the twist-lock receptacle to cause the ballast or driver to provide dimmable output from the light source; and a photo sensor operative to sense ambient light proximate the fixture assembly and to provide a sensed light signal or value to the dimming component, and where the dimming component is operative to selectively provide the dimming control value based at least in part on the sensed light signal or value. a fixture housing, at least one light source supported in the fixture housing, at least one ballast or driver supported in the fixture housing and electrically coupled to provide power to the light source, and a 3-terminal twist-lock receptacle mounted to the fixture housing and operative to receive a twist-lock connector; a controller module, comprising: a twist-lock type connector operatively coupled to the twist-lock receptacle and providing three class 1 electrical connections (118a-c) between the controller module and the fixture assembly, a dimming component operative to selectively provide at least one dimming control value to the ballast or driver through the twist-lock receptacle to cause the ballast or driver to provide dimmable output from the light source; and a photo sensor operative to sense ambient light proximate the fixture assembly and to provide a sensed light signal or value to the dimming component, and where the dimming component is operative to selectively provide the dimming control value based at least in part on the sensed light signal or value. a twist-lock type connector operatively coupled to the twist-lock receptacle and providing three class 1 electrical connections (118a-c) between the controller module and the fixture assembly, a dimming component operative to selectively provide at least one dimming control value to the ballast or driver through the twist-lock receptacle to cause the ballast or driver to provide dimmable output from the light source; and a photo sensor operative to sense ambient light proximate the fixture assembly and to provide a sensed light signal or value to the dimming component, and where the dimming component is operative to selectively provide the dimming control value based at least in part on the sensed light signal or value.