Ursus is Latin for "bear". In this form it refers to a male bear or the species regardless of gender; the specifically female form is Ursa. The word may also refer to:
- Ursus (praefectus urbi), praefectus urbi of Constantinople in 415-416
- Ursus (genus), a genus of bears
- Ursus (beer), a Romanian beer
- Ursus (vodka), an Icelandic vodka
- Ursus, Warsaw, a borough of Warsaw, Poland
- Ursus Tractor Factory, Poland
- Saint Ursus (disambiguation), the name of several Christian saints
- Reimarus Ursus (16th-century), an astronomer and imperial mathematician to Rudolf II
- Ursus (film character), a fictional character in Italian adventure films
- General Ursus (Planet of the Apes), a gorilla character in Beneath the Planet of the Apes
- Ursus, the bodyguard of Ligia, a minor character in Quo Vadis (novel)
- Ursus, a character in Victor Hugo's novel The Man Who Laughs
- Ursus (film), 1961 Italian film