The name Dionis is derived from the ancient Greek name Dionysios, which is ultimately rooted in the name of the Greek god Dionysus, the god of wine, vegetation, pleasure, festivity, and madness. Dionysios was a relatively common personal name among the ancient Greeks, particularly in the classical period from the 5th to 4th century BCE.

The name Dionysios is composed of the elements "Dio" meaning "divine" or "god", and "Nysos" meaning "Nysa", which was a mythological location associated with the birth and upbringing of the god Dionysus. The name can be interpreted to mean "son of Zeus" or "divine son", reflecting the mythological tradition that Dionysus was the son of Zeus and the mortal woman Semele.

One of the earliest recorded instances of the name Dionysios dates back to the 6th century BCE when it was borne by a Greek tyrant of Syracuse, Dionysios I (430-367 BCE), who ruled from 405 to 367 BCE. Another notable historical figure with this name was Dionysios of Halicarnassus (c. 60 BCE - after 7 BCE), a Greek historian and teacher of rhetoric who lived in the 1st century BCE.

During the Middle Ages, the name Dionysios underwent various transformations and adaptations in different languages and cultures. In Latin, it became Dionysius, and this form was adopted by several early Christian saints and martyrs, such as Saint Dionysius the Areopagite (c. 1st century CE) and Saint Dionysius of Paris (c. 3rd century CE), the patron saint of France.

The French form of the name, Denis, became popular during the medieval period, and several French kings bore this name, including Denis I (c. 629-638 CE), Denis the Little (c. 470-544 CE), a Scythian monk known for his work on canon law, and Denis Diderot (1713-1784 CE), the famous French philosopher and writer of the Enlightenment period.

The name Dionis is a variant spelling that emerged in various European languages, including Spanish and Portuguese. Notable historical figures with this spelling include Dionis Castell (c. 1595-1644), a Welsh mathematician and lawyer, and Dionis Zamudio (fl. 16th century), a Spanish navigator and explorer who participated in the Spanish conquest of the Philippines.