Vehicle lighting unit

A vehicle lighting unit can be configured to include a thin light guide. The vehicle lighting unit (1, 1B, 1C, 1D) can include: a solid light guide (3) having a light exiting surface (3a), a reflection surface (3b) opposite to the light exiting surface (3a), and a light incident surface (31) through which light enters the light guide so that the light reaches and is internally reflected off the light exiting surface (3a), then internally reflected off the reflection surface (3b), and exits through the light exiting surface (3a); and an LED light source (2) disposed to face to the light incident surface (31), for emitting light that enters the light guide through the light incident surface (31), is internally reflected off the light exiting surface (3a), is internally reflected off the reflection surface (3b), and exits through the light exiting surface (3a), wherein the reflection surface (3b) includes a plurality of divided reflection regions (a1 to a3, b1 to b3, c1 to c3), and the reflection regions includes at least one reflection region disposed at a reference position and at least one reflection region disposed at a position closer to the light exiting surface (3a) than the reference position.