Johann Faulhaber (5 May 1580 – 10 September 1635) was a German mathematician, specifically, a Rechenmeister.

Born in Ulm, Faulhaber was a trained weaver who later took the role of a surveyor of the city of Ulm. He collaborated with Johannes Kepler and Ludolph van Ceulen. In 1620, while in Ulm, Descartes probably corresponded with Faulhaber to discuss algebraic solutions of polynomial equations^[1]

He worked as fortification engineer in various cities (notably Basel, where he was fortification engineer from 1622 to 1624, and Frankfurt), and also worked under Maurice, Prince of Orange in the Netherlands. He also built water wheels in his home town and geometrical instruments for the military.

Faulhaber made the first publication of Henry Briggs's Logarithm in Germany. He is also credited with the first printed solution of equal temperament.^[2] He died in Ulm.

Faulhaber's major contribution was in calculating the sums of powers of integers. Jacob Bernoulli makes references to Faulhaber in his Ars Conjectandi.

Other than his mathematical work, he also worked on various mystical matters, such as alchemy, astrology and numerology. He was a member of the Rosicrucians. In 1619, after his involvement in the Ulm comet dispute, he published his work Fama Syderea Nova, containing prophecies in connection with the Great Comet of 1618 and the beginning of the Thirty Years' War. The Ulm comet dispute concerned whether the comets appearing during 1618 were signs sent by God, or just natural phenomena.^[3][4]