'Assisi' originates from Latin, specifically the word 'Asisium', where the original root is uncertain (possibly from a pre-Roman Umbrian or Oscan place-name root).

'Assisi' changed from the Latin word 'Asisium' and, through medieval Italian forms, eventually became the modern English form 'Assisi'.

Initially, it referred to the ancient Roman town 'Asisium'; over time the name came to denote the medieval and modern town 'Assisi', especially known for its association with St. Francis.