Montanus (/mɒnˈteɪnəs/; Greek: Μοντανός) was the second century founder of Montanism and a self-proclaimed prophet. Montanus emphasized the work of the Holy Spirit, in a manner which set him apart from the Great Church.

Little is known about the life of Montanus. Montanus used to be a pagan priest, but converted into Christianity. Montanus began his prophesying in a village called Ardabau, Phrygia. Montanus started prophesying circa 157–172, but Church Fathers give differing dates. Montanus was assisted by two women, Prisca and Maximilla, who also claimed to have prophecies.