A light source device includes: a first light source configured to emit first light including a white wavelength band or one or more wavelength bands of at least red, green, and blue； a second light source configured to emit second light including a specific wavelength band included in the first light； a first detector configured to detect an amount of the light of the specific wavelength band in the first light； a first optical member configured to multiplex light of a wavelength band different from the specific wavelength band in the first light, and the second light； and a processor configured to control the first light source based on a detection result of the first detector.
