The purpose of the present invention is to provide a head-up display device, and a lens unit, in which luminance unevenness of exit light exiting the lens unit is small even when an interval of lightsources arrayed in matrix is different between rows and columns. The head-up display device of the present invention is provided with: a plurality of light sources arrayed in matrix in a Y-direction and a Z-direction; and a lens unit (36) in which a convex lens portion (36b) for collecting radiant light radiated from the light sources is formed opposing each light source. The plurality of light sources are arranged at an interval A in a Z-direction and at an interval B, which is smaller than the interval A, in the Y-direction. The lens unit (36) has a first connection portion (a) and second connection portions (b) formed at boundaries of the adjacent convex lens portions (36b). The first connection portion (a) extends in the Y-direction, and the second connection portions (b) extend in theZ-direction. A width of a short direction of the first connection portion (a) is smaller than a width of a short direction of the second connection portions (b).