Epstein-Barr virus (EBV) homologues from non-human primates (NHPs) have been studied for nearly as long as EBV itself. Early serologic and DNA hybridization studies uncovered the existence of EBV-like lymphocryptoviruses (LCVs) across multiple NHP species. Subsequent molecular and genomic analyses revealed that LCVs from both humans and NHPs share strikingly similar colinear genome organization and encode homologous proteins expressed during both latent and lytic phases of infection, despite a level of species-specific restriction being present as shown by cross-infection experiments. Importantly, rhLCV infection in rhesus macaques faithfully recapitulates key aspects of EBV infection in humans, allowing for a powerful EBV surrogate animal model to study EBV infection and pathogenesis. In parallel, EBV susceptibility in the common marmoset offers a more accessible platform for EBV vaccine development with the potential to complement rhLCV studies. This chapter builds upon the First Edition of this work by taking the original text, beautifully crafted by Drs. Janine Mühe and Fred Wang, and updating it with relevant new insights and information. The updated chapter reviews over six decades of progress in characterizing LCVs that naturally infect primates, highlights the transformative use of rhesus macaques and common marmosets as experimental models of EBV infection, and explores how these systems are shaping the future of EBV research and vaccine development.