Jan III van Diest

Jan van Diest (died 1340) was bishop of Utrecht from 1322 to 1340. Born into a noble Brabantine family, he became provost of Cambrai before William III of Holland and Reginald II of Guelders backed him for the see; when the Utrecht chapters elected someone else, Pope John XXII annulled the election and consecrated him at Avignon.

His rule was marked by debt, nepotism and dependence on the two counts, who in 1331 even planned to partition the Sticht until local resistance saved the independence of the see. He was buried in the Dom Church of Utrecht.