A 12-yr-old mountain lion (Felis concolor) developed a 0.5-cm³ raised nonpigmented and nonulcerated mass between the lip and the nasal planum. The tumor was surgically removed and diagnosed histologically as a fibropapilloma. The tumor recurred 1 yr later, at which time it was again excised, and the diagnosis was reconfirmed by biopsy. Frozen tissue from the second excision was submitted for polymerase chain reaction testing for papillomavirus. The 176–base pair polymerase chain reaction product recovered from the tumor was cloned and sequenced. The papillomavirus had 96% homology with a papillomavirus previously retrieved from a fibropapilloma in a domestic cat and is the next most closely related to bovine papillomavirus type 1. This is the first report of a virus-associated fibropapilloma in a mountain lion.