Claudius Salmasius is the Latin name of Claude Saumaise (15 April 1588 – 3 September 1653), a French classical scholar.
Salmasius was born at Semur-en-Auxois in Burgundy. His father, a counsellor of the parlement of Dijon, sent him, at the age of sixteen, to Paris, where he became intimate with Isaac Casaubon (1559–1614). In 1606 he went to the University of Heidelberg, where he studied under the jurist Denis Godefroy, and devoted himself to the classics, influenced by the librarian Jan Gruter. Here he embraced Protestantism, the religion of his mother.
Returning to Burgundy, Salmasius qualified for the succession to his father's post, which he eventually lost on account of his religion. In 1623 he married Anne Mercier, a Protestant lady of a distinguished family. After declining overtures from Oxford, Padua and Bologna, in 1631 he accepted the professorship formerly held by Joseph Scaliger at Leiden. Although the appointment in many ways suited him, he found the climate trying. He became involved in a vicious controversy, over the Greek of the New Testament, with Daniel Heinsius. The quarrel became both highly personal and widely known, and Heinsius as university librarian refused him access to the books he wished to consult. Salmasius had an ally in Gerardus Vossius, on religious grounds.