Interferon-tau (IFNT), a multifunctional type I interferon, serves as a signal to maintain the corpus luteum (CL) during early pregnancy in domestic ruminants. Here we aimed to study whether IFNT directly affects the function of luteinized bovine granulosa cells (LGCs), used as a model for large luteal cells. Recombinant ovine IFNT (roIFNT) stimulated signal transducer and activator of transcription-1 (STAT1) and IFN-stimulated genes (ISGs; MX2, ISG15 and OAS1Y) in LGCs. The LGC also had high expression of IFN receptors (IFNAR1) and displayed a rapid and transient phosphorylation of STAT1 as well as an elevation in total STAT1 protein after longer incubation times (24-48h). These results indicate that IFNT activates type-1 interferon pathways in LGCs. In addition, IFNT treatment increased viable LGCs numbers and reduced dead and apoptotic cell counts in flow cytometry analyses using Annexin V staining. Consistent with these effects on cell viability, IFNT upregulated cell survival proteins (MCL1, BCLxL and XIAP) and decreased the levels of proteins implicated in apoptosis, gamma-H2AX, cleaved caspase 3 and thrombospondin-2 (THBS2). Notably, IFNT reversed the actions of thrombospondin-1, a potent luteal apoptotic factor, on cell viability as well as on XIAP and cleaved caspase 3 protein levels. Furthermore, roIFNT stimulated the mRNA concentrations for a series of proangiogenic genes such as FGF2, PDGFB and PDGFAR. In support of the in vitro observations, we found that CL tissue collected from day 18 pregnant cows had higher ISGs along with elevated levels of FGF2, PDGFB, THBS2 and XIAP as compared to CL from non-pregnant cows on day 18 of the estrous cycle. These findings show that IFNT activates diverse pathways in LGCs, promoting survival and blood vessel stabilization, while suppressing cell death signals. These mechanisms might contribute to CL maintenance during early pregnancy.