Risby was born in the parish of St. Lawrence, Reading, in 1489, and entered Winchester College in 1500. He was subsequently a fellow of New College, Oxford, taking his degree in 1510. He resigned in 1513 to enter the Franciscan Order, and eventually became guardian of the Observant friary at Canterbury.
Risby became a supporter of Dame Elizabeth Barton, O.S.B., widely known as the "Holy Maid of Kent", who had the reputation of being a visionary. When she declared that King Henry would soon die if he continued his actions against the papacy, a prophecy that failed to come to pass within the time she predicted, the king turned against her and she was condemned to death by an Act of Attainder (25 Henry VIII, c. 12), together with several of her supporters: Hugh Rich, O.F.M., guardian of the Observant friary at Richmond, Edward Bocking and John Dering, B.D. (Oxon.), both Benedictine monks of Christ Church, Canterbury, Henry Gold, M.A. (St. John's College, Cambridge), Parson of St. Mary Aldermanbury, London, and Vicar of Hayes, Middlesex, and Richard Master, M.A. (King's College, Oxon), Rector of Aldington, Kent, who was pardoned; but by some oversight Master's name was included and Risby's omitted in the catalogue of praetermissi.
Friar Thomas Bourchier, who took the Franciscan habit at Greenwich about 1557, wrote a work chronicling the lives of the Observant friars who were executed under the Tudors, In it he wrote that Risby and Rich had been offered their freedom twice, if they would accept the king's supremacy. Risby was executed by hanging along with the others, including Barton, at Tyburn, London, on 20 April 1534.
- Wainewright, John. "Richard Risby." The Catholic Encyclopedia. Vol. 13. New York: Robert Appleton Company, 1912. 12 Jan. 2013
- Historia Ecclesiastica de Martyrio Fratrum Ordinis Divi Francisci dictorum de Observantia, qui partim in Anglia sub Henrico octavo Rege, partim in Belgio sub Principe Auriaco, partim et in Hybernia tempore Elizabethæ regnantis Reginæ, idque ab anno 1536 usque ad hunc nostrum præsentem annum 1582, passi sunt. Paris. 1582.
- Gairdner, Letters and Papers of the reign of Henry VIII, VI, VII (London, Oxford, Cambridge, Edinburgh, and Dublin, 1882-3), passim;
- Francis Aidan Gasquet, Henry VIII and the English Monasteries (London, 1906), 44;
- Kirby, Winchester Scholars (London and Winchester, 1888), 98;
- Boase, Register of the University of Oxford (Oxford, 1885), 71.