Simon Episcopius (8 January 1583 – 4 April 1643) was a Dutch theologian and Remonstrant who played a significant role at the Synod of Dort in 1618.

Born in Amsterdam, in 1600 he entered the University of Leiden, where he studied theology under Jacobus Arminius, whose teaching he followed, and Franciscus Gomarus.

At the end of the Synod's sittings in 1619, Episcopius and the other twelve Arminian representatives were deprived of their offices and expelled from the country.

After the death (1625) of Maurice, prince of Orange, the violence of the Arminian controversy began to abate, and Episcopius was permitted in 1626 to return to his own country.

[1] Episcopius may be regarded as in great part the theological founder of Arminianism, since he developed and systematized the principles tentatively enunciated by Arminius.