A light source device includes at least one first wiring, a plurality of second wirings, a plurality of light emitting elements each having a lower-surface-side electrode connected to a respective one of the at least one first wiring, a plurality of protective elements each having a lower-surface-side electrode connected to a respective one of the plurality of second wirings each corresponding to a respective one of the plurality of light emitting elements, each of the plurality of protective elements connected to a respective one of the plurality of light emitting elements, a plurality of first wirings each connecting an upper-surface-side electrode of each of the plurality of light emitting elements and a respective one of the plurality of second wirings, a plurality of second wires each connecting the upper-surface-side electrodes of two adjacent ones of the protective elements; and a plurality of third wires each connecting an upper-surface-side electrode of a respective one of the plurality of protective elements and a corresponding one of the at least one first wiring. The upper-surface-side electrodes of the plurality of light emitting elements and the upper-surface-side electrodes of the plurality of protective elements are of a same polarity, and the plurality of first wires are disposed below the plurality of second wires.