Asellus may refer to:

• Asellus (genus), a genus of crustaceans
• Gamma Cancri, a star also known as "Asellus Borealis"
• Delta Cancri, a star also known as "Asellus Australis"
• Asellus (SaGa Frontier), one of multiple protagonists from SaGa Frontier
• Several men of Ancient Rome with this name:
  • Tiberius Claudius Asellus (praetor 206 BCE)
  • Tiberius Claudius Asellus (tribune of the plebs 139 BCE)
  • Publius Annius Asellus