Francis Gastrell (1662–1725) was bishop of Chester and a writer on deism. He was a friend of Jonathan Swift, mentioned several times in A Journal to Stella, and chaplain to Robert Harley, when Harley was speaker of the House of Commons.
He was born at Slapton, and educated at Westminster School and Christ Church, Oxford. He was Boyle Lecturer in 1697.
One of a group of Tory High Churchmen, he was on good terms with Francis Atterbury, George Smalridge and Robert Nelson, and one of the Commission of the end of the reign of Queen Anne. In 1714, the year of her death, he became bishop of Chester through Harley's influence. When Atterbury was put on trial in 1723, Gastrell spoke in his defence.