Originally developed as an Italian sword-and-sandal project, the cooperation and blessing of the Greek government allowed the producers to both finance and complete the production on a budget of 500,000 GBP () or approximately US$1,350,000 (), roughly twice for what most Italian peplum films were being made at the time. "The 300 Spartans" was the last film of Richard Egan's seven-year contract with 20th Century Fox. It was also the last film appearance of David Farrar, who then chose to retire from acting.