thumb|Portrait of Johannes Acronius by Frans Hals
Johannes Acronius (1565 – 29 September 1627) was a German Reformed theologian. He is less known by scientific works, than by his part in the quarrel between Arminians (Remonstrants) and Contra-Remonstrants (see History of Calvinist–Arminian debate).
Life
He was born in Grimersum, East Frisia, the son of a preacher, Bernardus Acronius, in a village north of Emden, now in the municipality of Krummhörn. He was taught by Zacharias Ursinus and Franciscus Junius in Neustadt an der Hardt, today Neustadt an der Weinstrasse. In 1584 he became a preacher in Eilsum, East Frisia, later in 1601 he was called to Groningen where he served for 10 years, during which time he was called several times to Amsterdam, but he refused as he did not want to take part in the arguments between Franciscus Gomarus and Jacobus Arminius.