A vehicular lamp having a structure of electrical connection between a lamp bulb serving as a light source installed in a lamp body and an external power source for supplying electric power to the lamp bulb which includes a back cover detachably attached to a bulb insertion hole formed in a back surface of the lamp body and a relay connector connecting with both the lamp bulb and an external power source, and the relay connector is constituted by an internal electrical connection section disposed at an inside of the back cover for electrically connecting with the lamp bulb and an external electrical connection section disposed at an outside of the back cover for connecting with a harness for the external power source. The internal electrical connection section and the external electrical connection section are formed integrally with each other by a conductive terminal which penetrates the back cover.