Jordanus is the Latin form of Jordan and refers to:

• Jordanus of Bristol, a saint venerated in Bristol, England
• Jordan Catala (Friar Jordanus), a 14th-century French missionary and explorer
• Jordanus de Nemore (Renaissance version: Jordanus Nemorarius), a medieval mathematician
• Jordanus of Saxony, c. 1190–1237, 2nd Master General of the Order of Preachers (Dominicans)
• Raymundus Jordanus, a 14th-century Christian writer also known as Idiota

It may also refer to:

• Jordanus (constellation), an obsolete constellation name