Outhier was born at La Marre-Jouserans, near Poligny, France, and studied at Dole and Besançon.
In 1726–1727 he presented a 5-inch-diameter celestial globe to the Académie Royale des Sciences, which demonstrated the movements of the sun and stars with a clockwork mechanism.
In 1733 he became involved in producing a map of France along with Bishop of Bayeux, Paul d'Albert de Luynes and took part in the triangulation surveys from Caen to St. Malo.
The expedition was led by Pierre-Louis Moreau de Maupertuis, with the scientists included being Alexis Claude Clairaut, Charles Le Monnier and Charles Etienne Louis Camus.
The Swedish scientist Anders Celsius was also involved and Outhier was included as physician, astronomer and maintainer of the journal of the expedition.