Gilles Quispel (30 May 1916 – 2 March 2006) was a Dutch theologian and historian of Christianity and Gnosticism. He was professor of early Christian history at Utrecht University.

Born in Rotterdam, after finishing secondary school in Dordrecht, Quispel studied classical philology from 1934 to 1941 at the Leiden University. At Leiden he also began to study theology, which he continued at the University of Groningen. Quispel completed his doctoral work in 1943 at Utrecht University with a dissertation examining the sources utilized in Tertullian's Adversus Marcionem. He devoted study to several Gnostic systems, particularly Valentinianism. In 1948-1949 he spent a year in Rome as a Bollingen fellow and was appointed professor of the history of the early Church at Utrecht University in 1951. Quispel served as a visiting professor at Harvard University in 1964-1965 and at the Katholieke Universiteit Leuven in 1968. He was engaged in first editing Nag Hammadi Codex I (the "Jung Codex") and devoted attention to the Nag Hammadi Library and particularly to the Gospel of Thomas throughout the rest of his career. Quispel also made contributions to the study of early "Jewish-Christian" traditions as well as Tatian's Diatessaron (a second-century gospel harmony). He died in El Gouna, Egypt.