Wilcox is known as one of the Oaten Hill Martyrs, as he was one of four Catholic clergy and laymen were martyred at Oaten Hill, Canterbury on 1 October, 1588. With him suffered two other priests, Christopher Buxton and Gerard Edwards (arrested under the name of Edward Campion), and a layman, Robert Widmerpool. Wilcox was the first of the four to be executed by hanging, drawing and quartering. It is recorded that he told his companions to be of good heart. He was going to heaven before them, where he would carry the tidings of their coming after him.