Red-bellied titi 
Red-faced spider monkey 
Red-handed tamarin 
Red-shanked Douc 
Red-tailed monkey 
Red-tailed sportive lemur 
Reddish-gray mouse lemur 
Rhesus macaque 
Ring-tailed lemur 
Rio Mayo titi 
Roloway monkey 
Saddleback Tamarin 
Sanfords brown lemur 
Scotts sportive lemur 
Senegal bushbaby 
Siamang 
Silky sifaka 
Silvery gibbon 
Silvery lutung 
Silvery Woolly Monkey 
Southern muriqui 
Southern pig-tailed macaque 
Southern plains gray langur 
Southern red-fronted brown lemur