Prevention and treatment options for FIP, a virulent pathotype of feline enteric coronavirus, are limited. Feline recombinant interferon omega is the most commonly available antiviral treatment, but its efficacy against FIP virus has not been well-demonstrated. ERDRP-0519 (ERDRP), a nonnucleoside inhibitor that targets RNA polymerase, is effective against in vitro and in vivo morbilliviruses. This study examined the in vitro efficacy of ERDRP against FIP virus. Results demonstrated significant inhibition of FIP virus replication in a dose-dependent manner, confirming ERDRP is highly effective against a coronavirus in vitro. Further study is needed to assess suitability of ERDRP in treatment of FIP virus in vivo.