Juan Eusebio Nieremberg y Ottín SJ (9 September de 1595 – 7 April 1658) was a Spanish Jesuit, polymath and mystic.

He studied Greek and Hebrew at the Colegio de Huete, arts and theology at Alcalá, and was ordained in 1623, making his profession in 1633.

At the Colegio Imperial de Madrid he taught humanities and natural history for sixteen years and Sacred Scripture for three.

As a director of souls he was much sought, being appointed by royal command confessor to the Duchess of Mantua, granddaughter of Philip II.

His works are distinguished for their erudition, those in Spanish being characterized according to Capmany, by nobility and purity of diction, terse, well-knit phrases, forcible metaphors, and vivid imagery.