Desiderius is a Latin given name, related to desiderium - which can be translated as "ardent desire" or "the longed-for". Various other forms include Desiderio in Italian, Desiderio or Desi in Spanish, Desidério in Portuguese, Didier in French and Dezső in Hungarian.

Desiderius may refer to:

• Desiderius (died c. 786), the last king of the Lombard Kingdom of northern Italy
• Desiderius, Abbot of Monte Cassino (c. 1026–1087), successor of Pope Gregory VII
• Desiderius Erasmus (c. 1466–1536), Dutch humanist and theologian
• Desiderius Hampel (1895-1981), Waffen-SS general
• Desiderius of Aquitaine (died 587), Gallo-Roman dux in the Kingdom of the Franks
• Desiderius Wein (1873-1944), Hungarian doctor and gymnast