The John Wick film series has several references to Greek mythology, which add depth to the story and characters.
One of the most prominent references is the use of the name "John Wick" itself, which is a nod to the historical figure of John Wycliffe, who was an English theologian and translator of the Bible into English. Wycliffe's name is derived from the Old English "Wic", meaning "settlement", which is similar to the Greek word "oikos", meaning "household". In Greek mythology, Oikos is also the name of a deity associated with the household and domestic life.
Another notable reference is the name of the fourth installment of the series, "John Wick: Chapter 4", which is a reference to the ancient Greek epic poems, such as Homer's "The Odyssey" and "The Iliad", which were divided into chapters or "books".
In the first John Wick film, the character of Viggo Tarasov is said to have owned a nightclub called "The Red Circle", which may be a reference to the three-headed dog Cerberus, who guards the entrance to the underworld in Greek mythology.
In the second John Wick film, the character of Winston is shown speaking to a man who could be interpreted as a nod to Charon, the ferryman who transports the souls of the dead across the river Styx to the underworld.
Finally, in John Wick 3, the character of Sofia, played by Halle Berry, is shown with two Belgian Malinois dogs named after Greek mythological figures, one of them being named Achilles, the famous Greek warrior and protagonist of Homer's epic poem, "The Iliad".
John Wick 4
Chapter 4 picks up where the third left off. After John broke the Continental's policy of killing on hotel grounds, he traveled to Rome to find the location of the one who sits above The High Table to challenge his excommunicado status. After re-establishing his devotion to The High Table, John joined forces with New York Continental manager Winston and his concierge Charon to battle High Table representatives after the hotel was deconsecrated because Winston allowed John to escape. In the shocking conclusion, John gets shot by Winston on the roof to appease The High Table and saved by the Bowery King, who vows to make The High Table pay. In the latest installment, John, for the first time, actively seeks to vanquish The High Table.