Jesuit ecclesiastical historian known for his major role in the compilation of the Acta Sanctorum, a vast collection of lives of the Christian saints, and as the founder of the Bollandists, a small group of Jesuits who continued to edit and publish the collection. Apart from containing extensive amounts of biographical material, this work is distinguished for its use of the principles of historical criticism.

Little is known of Bolland's life. In 1629 he was chosen to continue the hagiographic work of the priest Héribert Rosweyde, who initiated the Acta Sanctorum. Bolland, in collaboration with his associate Henschenius (Godefroid Henskens), modified and extended the original plan of the Acta; he arranged the saints according to the date of their deaths, included doubtful cases (but with notes), and added indexes, chronologies, and histories to each chapter. The parts completed during his life were January (2 vol., 1643) and February (3 vol., 1658), containing the biographies and legends of the saints whose feast days fell in those two months.

In his researches Bolland corresponded and travelled widely, investigating previously unexamined sources in Italian libraries. His work was continued by his disciples, Henschenius and Papebroch (Daniel van Papenbroeck), and then carried on by later hagiographers.