The Danfoss' mouse lemur or the Ambarijeby mouse lemur (Microcebus danfossi), is a species of mouse lemur endemic to Madagascar. It lives in western deciduous forest within a limited range between the Sofia River and the Maevarano River. It is a relatively large reddish mouse lemur with a total length of 25 to 29 centimeters, including 15 to 17 centimeters of tail.