There is provided a liquid crystal display device which can easily be made thin and which is capable of high-quality displaying, as well as a mobile electronic device having the same.A liquid crystal display device according to the present invention includes: a first substrate; a second substrate disposed so as to be closer to a viewer than the first substrate is; a liquid crystal layer provided therebetween; and a linear light source provided by a side of the first substrate, the linear light source emitting light toward a side face of the first substrate. The first substrate includes a selective reflection layer for selectively reflecting light of a specific polarization state, and the linear light source includes a point light source and a linear light guiding member for guiding light emitted from the point light source to the side face of the first substrate. The linear light guiding member includes: a selective-reflection portion for selectively reflecting light of a first polarization state out of light which enters into the linear light guiding member from the point light source; and a polarization conversion portion for, out of the light which enters into the linear light guiding member from the point light source, converting light of a second polarization state into light of the first polarization state, the second polarization state being different from the first polarization state.