An endoscope illumination device includes a light source that outputs primary light, a light guide that includes a first end face from which the primary light is radiated, and guides the primary light, and a light converter that is disposed to face the first end face, includes a second end face which the primary light enters, converts part of the primary light into secondary light. The illumination device also includes a holder that holds the light guide and the light converter so that an incident angle of the secondary light that is radiated from a point of intersection of the second end face and an optical axis of the light guide on the first end face and enters the first end face is equal to or larger than an acceptance angle (NA) of the light guide.