Bradypus tridactylus is found in lowland and montane tropical moist forest. In Suriname and French Guiana the species has not been observed in mangroves, but it occurs in the swamp and marsh forests immediately adjacent to them (M. Pool pers. comm. 2022; B. de Thoisy pers. comm. 2022). It has been recorded on tepuis (table-top mountains).

Adult sloths are light to dark grey with a unique pattern of darker areas. The head and throat range in colour from white to orange-yellow. Males can be distinguished from females by their dorsal patch of shorter hairs consisting of a central black line pattern in combination with orange-yellow hair. This dorsal patch has a unique pattern for each individual. The dorsal patch only forms around the age of around one year prior to which the animals cannot be sexually distinguished from external features. Both males and females reach reproductive age at three to six years. A single young is born after a gestation of six months (Taube et al. 2001).