Father James Cullen, S.J. (19 April 1867 – 7 December 1933) was born at Drogheda, County Louth, Ireland.
He studied mathematics at the Trinity College, Dublin for a while, but eventually turned to theology and was ordained as a Jesuit on 1 July 1901.
In 1905, he taught mathematics at Mount St. Mary's College in Derbyshire and published his finding of what is now known as Cullen numbers in number theory.
- Keller, Wilfrid (1995). New Cullen primes. Math. Comp. 64, 1733–1741.