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). His primary works were to counter Roman Catholic doctrine (especially that championed by Robert Bellarmine) and to oppose Socinianism and Arminianism.
Lubbertus was born in Langwarden in 1555. He studied Divinity in Wittenberg in 1574 and in Geneva in 1576, where one of his professors was Theodore Beza. He also studied in Marburg in 1578 and at Neustadt an der Weinstraße in 1580, where one of his teachers was Zacharias Ursinus. He earned his doctorate in theology on June 22, 1587 in Heidelberg under Daniel Tossanus.
Around 1592 Hadrian à Saravia, who had left the Netherlands for England, wrote in his De Gradibus complaining that the Netherlands' governmental pay of fixed stipends to ministers was far too small and "evidence that the church's officers were not shown the respect that was their due...he spoke of the 'misera conditio' of ministers in Holland. The government behaved towards them like an employer." Saravia found that his local officials held that giving ministers too much money would make them "grow in respect and authority in the eyes of the people" and make them rivals of the burgomasters and sheriffs.Theodore Beza already under attack from Leiden professor, Carolus Gallus (who questioned his "views on election, creation, the relationship between church and state and church order") saw Saravia's work as a further attack on his Church. Beza wrote to Lubbertus in 1592 expecting support. Lubbertus did not come to the aid of Calvin's successor, feeling that as Saravia was in the Anglican Church that his views would not have the power of appeal in the Netherlands that Beza feared.