A lamp assembly (100) includes a lamp base (3) defining a socket, with a mounting portion (33) arranged therein; a pair of cables (4) inserted into the socket via a cable passage defined in a rear portion of the lamp base, with conductors of the cables extending through passageways in the mounting portion and configured to hook thereon; a lamp holder (2) having a body portion inserted into the socket of the lamp base together with the mounting portion to sandwich the conductors; and a lamp bulb (1) held by the lamp holder, with a pair of legs thereof inserted into the socket and contacting conductors of the cables.