Born in Saint-Symphorien, France, Champier was a relation of the Chevalier de Bayard through his wife, Marguerite Terrail.
A doctor of medicine at Montpellier, Champier was the personal physician of Antoine, Duke of Lorraine, whom he followed to Italy with Louis XII, attending to several battles, and finally settling in Lyon.
His fame was considerable in Lyon, which in the 16th century was the greatest manufacturer of medical books in France, with editors such as Sébastien Gryphe.
He was an extreme opponent to Renaissance occultism, and wrote in 1532 an Epistola campegiana de tranmutatione metallorum contra alchimistas.
Champier added a codicil to his last will in May 1539, and he is not noticed in any document after this date, so historians believe that he died in the second part of 1539.