Vehicle lamp and optical unit thereof

A vehicle lamp (1) includes a light emitting device (52a) having a rectangular light emitting surface (52af) and disposed such that the long sides (52af1) of the light emitting surface (52af) extend in a vertical direction, and a reflector (54b) configured to reflect light from the light emitting device (52a) in a forward direction of the vehicle lamp (1) to form a horizontally diffused light distribution pattern (P1, P2). The reflector (54b) is configured to reflect the light from the light emitting device (52a) such that the long sides (52af1) of the light emitting surface (52af) are projected to extend in a vertical direction (V) of the horizontally diffused light distribution pattern (P1, P2), and such that, in a top view of the vehicle lamp (1), a part (A) of the light reflected by one end portion (54b1) of the reflector (54b) and another part (B) of the light reflected by another end portion (54b2) of the reflector (54b) intersect each other.