This species occurs in the tropical/subtropical dry forest in the west, and tropical moist lowland and montane forest in the east. Groups vary in size from 3-12 (larger on Mayotte) and home ranges on Madagascar vary from approximately seven to 20 ha (Mittermeier et al. 2010). Recently groups of up to 13 individuals have been recorded in the mid- to high-elevation Ankeniheny-Zahamena Corridor, with a mean group size of five (H.L.L. Randrianarimanana/The Aspinall Foundation, unpublished data). The diet consists largely of fruits, young leaves, and flowers, supplemented with bark, tree exudates, soil, bird eggs and animal prey (including insects, centipedes, millipedes, nestlings, chameleons and frogs). Animals sometimes consume fruit from cultivated trees such as guava, which may bring them into conflict with humans. This species is cathemeral (active during both daylight and nighttime hours); at Ampijoroa the degree of nighttime activity was highest in the dry season; during the rainy season the species was largely diurnal (Ratsirarson and Ranaivonasy 2002, Rasmussen 2005). The mating season is in May and June. Most adult females produce offspring each year. One or two young are born in September or October, after a gestation period of around 120 days. Weaning occurs at 6–7 months, and sexual maturity at between 1–2 years. Individuals may live up to 30 years.

This species is found in Madagascar in three populations. First, it is found in the west, between the Betsiboka River in the south and the Mahavavy du Nord River in the north (including several scattered forest fragments on the central plateau). Second, there is an isolated population in Ambohitantely Special Reserve (a small reserve of no more than 3,000 ha in the central plateau northwest of Antananarivo). Finally, this species has an eastern rainforest distribution from approximately the Ambatovaky Special Reserve in the north, to the Onive and Mangoro Rivers in the south (with additional small populations just south of the Mangoro River in the Vohitrambo and Vohibe forests; Rajaonson and King 2013). They are also on the island of Mayotte, where the species apparently was introduced by human agency (Mittermeier et al. 2010), however this population is possibly of partly hybrid origin (Mittermeier et al. 2008, 2010). 

The western population can be divided into two subpopulations, a southern one extending from the Betsiboka River/Ankarafantsika National Park north to the Maevarano River, and a northern one ranging from the Andranomalaza River and Manongarivo Reserve to the Mahavavy du Nord River south of Ambilobe. Animals in the northern reaches of this range may also be found throughout the moister forests of the Sambirano region, as well as on the slopes of the Tsaratanana Massif, and are very similar in colouration to the Brown Lemurs found on the island of Mayotte (Mittermeier et al. 2010). It ranges from sea-level to 1,880 m.

It has been estimated that there will be a 46% reduction in the species' range from 2000 to 2080 due to climate change alone (Brown and Yoder 2015).

This species is likely affected by national trends in forest habitat loss: Madagascar lost 37% of its forest cover from 1973 to 2014, with an annual deforestation rate of 1.1%/year from 2010 to 2014. Almost half of Madagascar's forest (46%) is now located within less than 100 metres from the forest edge (Vieilledent et al. 2018).

This species is listed on Appendix I of CITES. This species is reported to occur in four national parks (Ankarafantsika, Andasibe-Mantadia, Andringitra, and Zahamena), two strict nature reserves (Tsaratanana and Zahamena), and seven special reserves (Ambatovaky, Ambohitantely, Analamazaotra, Bora, Mangerivola, Manongarivo, Marotandrano and Tampoketsa-Analamaitso) and other newer protected areas in lower protection categories (Corridor Ankeniheny-Zahamena, Maromizaha, Mangabe and Tampolo) (Mittermeier et al. 2010). The population in Bora Special Reserve may be extirpated due to extreme levels of deforestation within the reserve.

Several hundred Eulemur fulvus hybrids also inhabit the little island of M’Bouzi, off Mayotte in the Comoros, which serves as an unofficial lemur sanctuary. However, all E. fulvus in the Comoros may be of partially hybrid origin.