Clergyman and Protestant reformer. Willcock first appears as a Dominican Friar in Ayr, and was probably born thereabouts. He was educated at the University of Glasgow and in Europe, most-likely Cologne. He went to England but was imprisoned in the Tower of London in 1541 owing to his support of a reformed church. After the death of King Henry VIII, he appears as a preacher in Loughborough, enjoying a good living probably through the influence of the Dowager Duchess of Suffolk, for whom Willcock had been Chaplain eight years previously. He supported Lady Jane Grey, daughter of the Duke of Suffolk, as Queen but this brought a charge of treason and Willcock fled to the Continent in 1554. TIme in the Netherlands re-inforced the principles of Reformation in Willcock and he returned to Scotland in 1558. He preached at St. John's Church in Ayr, was accused of heresy but failed to appear before Mary of Guise (1515-60) to answer the charge. In 1559, he went to Perth before coming to St. Giles Kirk in Edinburgh to work with John Knox (c.1513-72) as the Reformation had taken hold.
In 1560, Willock was appointed to assist in preparing the Book of Discipline and was also involved in writing the Confession of Faith. He also served as Moderator of the General Assembly of the Church of Scotland (1562, 1564-65, and 1568).
Thereafter Willcock returned to his parish in Loughborough, which is where he eventually died and was buried.
