The reddish hermit (Phaethornis ruber) is a species of bird in the family Trochilidae, the hummingbirds. It is found in Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela, and the Guianas.
The reddish hermit is 8 to 9 cm long and weighs 1.8 to 3 g. All subspecies are generally dark green and rufous on the upperparts and cinnamon rufous on the underparts. Males have a black band on the chest and the tail feather have narrow white or reddish tips. Females have lighter underparts than the males. P. r. episcopus is about the same size as the nominate but has orange-rufous rather than cinnamon-rufous underparts and white tips to the tail. P. r. nigricinctus is the smallest subspecies; it has the richest rufous underparts. P. r. longipennis is the largest subspecies. It has a whitish chin and its central tail feathers have rufous tips.