Stacy Keach as Martin Luther

Hugh Griffith as Tetzel

Judi Dench as Katharina

Peter Cellier as Prior

Leonard Rossiter as Brother Weinand

Patrick Magee as Luther's Father

Thomas Heathcote as Friend

Julian Glover as Knight

Matthew Guinness as Reading Knight

Peter Kenvyn as Praying Monk (uncredited)

Tom Baker as Pope Leo X

Malcolm Stoddard as Emperor Charles the Fifth

Bruce Carstairs as Duke Frederick Elector of Saxony

Robert Stephens as Johann von Eck

Alan Badel as Cardinal Cajetan de Vio

Maurice Denham as Johann von Staupitz Vicar General