The earlier and better known John Leland (1502 - 1552) was an English antiquary. He was born in London and educated at both Oxford and Cambridge. He served as first chaplain, then librarian, to king Henry VIII. He was appointed Royal Antiquarian in 1533, and in this post travelled through England collecting historical and geographical material for publication in a single comprehensive work. A mental breakdown in 1550 prevented him from completing this work.
Another John Leland (1691 - 1766) was a Presbyterian minister and author of theological works. Born in Wigan, Lancashire, he was educated in Dublin, Ireland (then part of Great Britain), and went into the ministry there. His main interest was in opposing Deism, and he attacked proponents of Deist ideas, such as Matthew Tindal.
A third John Leland (1754 - 1841) was a Baptist minister in Massachusetts and Virginia. He was an important figure in the struggle for religious liberty in the United States. Leland also later opposed the rise of missionary societies among Baptists. He was born on May 14, 1754, in Grafton, Massachusetts and died on January 14, 1841 in Cheshire, Massachusetts.