Lambert Simnel (circa 1477 - circa 1534) was a child pretender to the throne of England. Together with Perkin Warbeck, he was one of two impostors who threatened the rule of Henry VII of England (reigned 1485 - 1509) during the last decade of the fifteenth century.

Lambert Simnel was born in about 1477. Different sources have different claims of his parentage from a baker and tradesman to organ builder. At the age of about ten, he was taken as a pupil by an Oxford-trained priest named Roger Simon (or Richard or Symonds) who apparently decided to become a kingmaker. He tutored the boy in courtly manners and contemporaries did describe the boy as handsome.

Originally Simon intended to present Simnel as Richard of York, son of Edward IV. However, when he heard rumors that Edward, Earl of Warwick had died during his imprisonment in the Tower of London, he changed his mind. The real Edward was a boy of about the same age who was a genuine claimant to the throne because he was the son of George, Duke of Clarence.

Simon spread a rumor that Edward had actually fled from the tower and was under his guardianship. He gained some support from the House of York. He took Simnel to Ireland where there was still support of Yorkists and presented him to the Earl of Kildare. Earl was willing to support the story and invade England to overthrow King Henry. On May 24 1487 Simnel was crowned in Christchurch Cathedral, Dublin in Ireland as "King Edward VI". The Earl of Kildare collected an army of Irish soldiers under the command of Thomas Geraldine.

When Henry Tudor heard about the matter, he also knew that he had the real Edward of Warwick still imprisoned in the Tower. On February 2 1487 he presented the Edward in public in an attempt to prove that the young pretender was an impostor. Henry also declared a general pardon of all offenses, including treason against himself, on the condition that offenders submit to him.

John de la Pole, Earl of Lincoln and designated successor to late King Richard III of England, joined the conspiracy against the king and fled to Flanders. There he claimed that he had had a hand in young Warwick's escape. There he also met Lord Lovell who had supported failed Yorkist uprising in 1486. Margaret of Burgundy collected 2000 Flemish mercenaries under the command of Martin Schwarz and shipped them to Ireland. They arrived in Ireland on May 5. Henry was informed of this and began to gather troops.

Simnel's supporters—mainly composed of Flemish and Irish troops—landed near Furness in Lancashire in June 5 1487 and were joined with some English supporters. However, most local nobles aside from Thomas Broughton did not join them. They clashed with Henry's army on June 16 at the Battle of Stoke Field and were defeated. The Earl of Kildare was captured, and the Earl of Lincoln, Broughton, and Schwarz were killed. Lord Lovell went missing and there were rumors that he had escaped and hidden to avoid retribution. Simon avoided execution due to his priestly status but was imprisoned for life.

Henry VII pardoned young Simnel (possibly because he had been mostly a puppet in the hands of adults) and gave him a job in the royal kitchen. When he grew older, he became a royal falconer. He died in about 1534.