Disclosed are a fluorescence microscope light source apparatus and a fluorescence microscope capable of obtaining high-luminance light in a wavelength of 500 to 550 nm and having reduced background noise when a sample is observed. The fluorescence microscope light source apparatus to be installed in a fluorescence microscope including an illumination light bandpass filter includes: a laser diode that emits blue light as excitation light; a phosphor that converts the excitation light from the laser diode into illumination fluorescence with a wavelength region of 500 to 550 nm; an optical system that extracts the illumination fluorescence from the phosphor; a first condenser lens that condenses the excitation light onto the phosphor; a light guide body having one end face on which the illumination fluorescence is incident and the other end face from which the illumination fluorescence exits; and a second condenser lens that condenses the illumination fluorescence onto the one end face of the light guide body. A band-elimination filter that blocks or attenuates light, out of the illumination fluorescence, in a wavelength region including a transmission maximum wavelength and including no transmission minimum wavelength in the illumination light bandpass filter is provided on a light path of the illumination fluorescence.