Walter Haddon LL.D. (1515–1572) was an English civil lawyer, much involved in church and university affairs under Edward VI, Queen Mary, and Elizabeth I. He was a University of Cambridge humanist and reformer, and was highly reputed in his time as a Latinist. He sat as an MP during the reigns of Mary and Elizabeth. His controversial exchange with the Portuguese historian Jerónimo Osório attracted international attention partly on account of the scholarly reputations of the protagonists.