German author and religious leader who was responsible for initiating the Protestant Reformation at Strassburg (Strasbourg).

He became a lecturer (1511) and rector (1517) at Freiburg im Breisgau, moving to Strassburg in 1518 to become minister of the Roman Catholic cathedral there. In 1521, however, he accepted the Reformation doctrines of Martin Luther and began to preach in an evangelical manner to his congregation. Although condemned by the Roman Catholic clergy, he continued as cathedral minister with the protection of the magistrates and parishioners. He replied to the attacks by his bishop in his Christliche Verantwortung (1523; “Christian Response”), a discussion of the scriptural basis for the Reformation. He also assembled a number of his writings in the form of a catechism, Frag und Antwort (1536; “Question and Answer”). Although eclipsed in Strassburg by the reformers Wolfgang Capito (Capito, Wolfgang Fabricius) and Martin Bucer (Bucer, Martin), Zell's pastoral role in establishing the Reformation in the city was significant.