Disclosed are a lamp for a vehicle, and a lamp assembly for a vehicle.. The lamp for a vehicle includes a first light source (20) that emits a first light along a first direction (D1) that is perpendicular to an upward/downward direction, a refractor (10) that refracts the first light emitted from the first light source (20), a second light source (30) that emits a second light toward the refractor (10) along a second direction (D2) that crosses the first direction (D1), and a third light source (40) disposed adjacent to the second light source (30), and that emits a third light toward the refractor (10) along the second direction (D2).