(1500?–55), English Protestant prelate, reformer, and martyr, born near Willimoteswyke, Northumberland, and educated at Pembroke Hall, University of Cambridge, and the universities of Paris and Louvain. He returned to Cambridge as junior treasurer of his college, thereafter becoming university proctor and, finally, chaplain to the university. In 1537, having shown leanings toward the Reformation, he was made chaplain to Thomas Cranmer, then archbishop of Canterbury, and received other ecclesiastical preferences. He became chaplain to King Henry VIII in 1541.

During the reign of Edward VI Ridley rose to prominence. He had by this time renounced the doctrine of transubstantiation. In 1547 he was named bishop of Rochester. Ridley helped Cranmer to compile the Book of Common Prayer and the Thirty-nine Articles and was appointed to help establish Protestantism in the University of Cambridge. In 1550 he became bishop of London. After the death of Edward, Ridley supported Lady Jane Grey as successor to the throne and publicly pronounced both of King Henry VIII’s daughters, Mary and Elizabeth, illegitimate.

When Mary, a Roman Catholic, was proclaimed queen he was imprisoned in the Tower of London, where he wrote statements defending his religious opinions. In 1554, refusing to recant, he was declared a heretic and excommunicated, and in 1555 he was tried under the penal laws instituted by the Catholic queen, which provided for the execution of heretics. Ridley was burned at the stake with the English prelate and reformer Hugh Latimer. His writings (Works) were published in 1841.