Sibrandus Lubbertus (c.1555–1625) (also referred to as Sibrand Lubbert or Sybrandus Lubbertus) was a Dutch Calvinist theologian and was a professor of theology at the University of Franeker for forty years from the institute's foundation in 1585. He was a prominent participant in the Synod of Dort (1618–1619).

Born in the Frisian hamlet of Langwarden circa 1555, the redoubtable Sibrandus Lubbertus grew, by God’s providence, into a chief bulwark of Reformed orthodoxy: trained first at Wittenberg, then at Geneva beneath the venerable Théodore Beza, at Marburg, and at Neustadt under Zacharias Ursinus, he was crowned Doctor of Sacred Theology at Heidelberg on 22 June 1587 under Daniel Tossanus. From the founding of the Academy of Franeker in 1585 until his death there on 10 January 1625, this indefatigable professor expounded the whole body of divinity with a rigor both scholastic and pastoral, wielding the dialectical sword against the triple hydra of Popery, Socinianism, and Arminian novelty. His De conciliis libri quinque (1601) unmasked Bellarmine’s Roman sophistries; his massive Commentarii ad XC errores Conradi Vorstii and subsequent Responsio ad Pietatem Hugonis Grotii (1614) exposed the lurking venom of heterodoxy and civil Erastianism, drawing even King James I of England into the fray. At the Synod of Dort (1618–1619) he stood as a pillar among the Contra-Remonstrants, defending the Canons with consummate learning and holy zeal. Thus lived and labored Lubbertus—scholastic in method, Puritan in temper—ever contending for the faith once delivered unto the saints.

Born in the Frisian hamlet of Langwarden circa 1555, the redoubtable Sibrandus Lubbertus grew, by God’s providence, into a chief bulwark of Reformed orthodoxy: trained first at Wittenberg, then at Geneva beneath the venerable Théodore Beza, at Marburg, and at Neustadt under Zacharias Ursinus, he was crowned Doctor of Sacred Theology at Heidelberg on 22 June 1587 under Daniel Tossanus. From the founding of the Academy of Franeker in 1585 until his death there on 10 January 1625, this indefatigable professor expounded the whole body of divinity with a rigor both scholastic and pastoral, wielding the dialectical sword against the triple hydra of Popery, Socinianism, and Arminian novelty. His De conciliis libri quinque (1601) unmasked Bellarmine’s Roman sophistries; his massive Commentarii ad XC errores Conradi Vorstii and subsequent Responsio ad Pietatem Hugonis Grotii (1614) exposed the lurking venom of heterodoxy and civil Erastianism, drawing even King James I of England into the fray. At the Synod of Dort (1618–1619) he stood as a pillar among the Contra-Remonstrants, defending the Canons with consummate learning and holy zeal. Thus lived and labored Lubbertus—scholastic in method, Puritan in temper—ever contending for the faith once delivered unto the saints.

Disputations:

Theological Disputations; The Second Disputation; Concerning God & His Attributes; (Aegidius Radæus, 1609)