After attending Steyning School in Sussex, John Pell entered Trinity College, Cambridge in 1624. He received his B.A. in 1628 and his M.A. in 1630.
After leaving Cambridge, Pell became a schoolmaster. He worked first in Horsham, then in Chichester. He spent five years from 1638 teaching mathematics in London. He then went abroad becoming Professor of Mathematics at a College in Amsterdam from 1643 until he took up a similar post the University of Breda in 1646.
Pell returned to England in 1652 and was appointed by Oliver Cromwell to a post teaching mathematics in London. He spent the years 1654 to 1658 holding a government post in Zurich. On his return to England became a vicar and remained in this position in the church for the last 20 years of his life.
Pell worked on algebra and number theory. He gave a table of factors of all integers up to 100000 in 1668. Pell's equation y2 = ax2 + 1, where a is a non-square integer, was first studied by Brahmagupta and Bhaskara. Its complete theory was worked out by Lagrange, not Pell.
It is often said that Euler mistakenly attributed Brouncker's work on this equation to Pell. However the equation appears in a book by Rahn which was certainly written with Pell's help: some say entirely written by Pell. Perhaps Euler knew what he was doing in naming the equation.
Pell published a number of works, for example Idea of Mathematics (1638) and Controversiae de vera circuli mensura (1647), this second work being written because of a dispute Pell was involved in over the value of p.
He also translated Lansberge's tables, which were published in 1632, and also worked on astronomy.
Pell was elected to the Royal Society in 1663.