Neostoicism was a philosophical movement that arose in the late 16th century from the works of Justus Lipsius, and sought to combine the beliefs of Stoicism and Christianity. Lipsius was Flemish and a Renaissance humanist. The movement took on the nature of religious syncretism, although modern scholarship does not consider that it resulted in a successful synthesis. The name "neostoicism" is attributed to two Roman Catholic authors, Léontine Zanta and Julien-Eymard d'Angers.

Justus Lipsius was a Flemish Catholic philologist, philosopher, and humanist. Lipsius wrote a series of works designed to revive ancient Stoicism in a form that would be compatible with Christianity. The most famous of these is De Constantia. His form of Stoicism influenced a number of contemporary thinkers, creating the intellectual movement of Neostoicism. He taught at the universities in Jena, Leiden, and Leuven.