Thomas Netter (c. 1375 – 2 November 1430) was an English Scholastic theologian and controversialist. From his birthplace he is commonly called Thomas of Walden, or Thomas Waldensis.
Born at Saffron Walden, Essex, as a young adult he entered the Carmelite Order in London, and pursued his studies partly there and partly at Oxford, where he took degrees, and spent a number of years in teaching, as may be gathered from the titles of his writings (the actual works being for the greater part lost), which embrace the whole of philosophy, Scripture, canon law, and theology, that is, a complete academical course. He was well read in the classics and the ecclesiastical writers known at the beginning of the fifteenth century, as is proved by numerous quotations in his own writings. Only the dates of his ordinations as acolyte and subdeacon are on record, 1394 and 1395.
His public life began in 1409, when he was sent to the Council of Pisa, where he is said to have upheld the rights of the council. Back in England he took a prominent part in the prosecution of Wycliffites and Lollards, assisting at the trials of William Taylor (1410), Sir John Oldcastle (1413), William White (1428), preaching at St. Paul's Cross against Lollardism, and writing copiously on the questions in dispute ("De religione perfectorum", "De paupertate Christi", "De Corpore Christi", etc.). The House of Lancaster having chosen Carmelite friars for confessors, an office which included the duties of chaplain, almoner, and secretary and which frequently was rewarded with some small bishopric, Netter succeeded Stephen Patrington as confessor to Henry V of England, and provincial of the Carmelites (1414). No political importance seems to have been attached to such positions.