This article examines the sepulchral monuments commissioned by Pius V (1566–1572), which include a mausoleum for himself and three tombs for men he held in high esteem. These projects have never before been discussed together and the author reconstructs the circumstances surrounding each of the commissions to demonstrate the personal and political motivations behind them. The author also considers their use of coloured marbles, looking particularly at how this relates to the paragone between painting and sculpture, concluding that these important papal commissions were not only informed by the reforming demands of their patron but by contemporary artistic theory.