Gamma-herpesviruses are widespread, oncogenic pathogens that chronically infect circulating lymphocytes and cause lymphocytic cancers. How lymphocyte infection is first established is not well understood because it precedes clinical presentation. However the spleen is known to provide an important general check-point for circulating pathogens and a specific focus of gamma-herpesvirus persistence. We find by in situ analysis and cre-lox genetic marking that Murid Herpesvirus-4 first enters the spleen not via lymphocytes, but by infecting its marginal zone (MZ) macrophages. These provided a conduit to MZ B cells, which then relocated to the white pulp and transferred virus to follicular dendritic cells. Infection then reached germinal center B cells. When mice lacked MZ B cells, or were treated with a sphingosine-1-phosphate receptor agonist to dislocate them; or when the virus was attenuated in intercellular spread, host colonization was impaired. Thus, lymphoid infection involved serial virus exchanges between myeloid and lymphoid cell that followed host pathways but were enhanced by viral genes. Important implications are that gamma-herpesvirus lytic functions could be good vaccine targets, and that targeting inter-cellular exchanges could limit chronic infection.