Producer Art Linson and David Mamet were having lunch when Linson informed Mamet that he could not get anything more than a no frills budget for the movie. Val Kilmer was literally at the next table. Linson knew Kilmer and asked him to come over, and they talked about the production. Kilmer was so impressed with the story and Mamet's vision that he agreed to the role giving a significant discount to facilitate Franchise Pictures giving a green-light to the production.
David Mamet incorporated a number of real life experiences from various U.S. special forces members for the production, including Eric L. Haney who had served in highly classified operations during his 20-year military career. Haney's experience included front-line combat units as a combat infantryman, as an Army Ranger, and as a founding operator within the elite Delta Force under Colonel Charlie Beckwith. These experiences helped Haney effectively serve as a technical advisor, weapons expert, and actor's mentor to Val Kilmer, ensuring that Kilmer reflected an accurate depiction of a special forces operative in every capacity. Haney retired as a highly decorated Sergeant Major, and his documented experience also includes security surveys, metro SWAT team arms training, oil company guard force management, executive protection, and the recovery of American children kidnapped and taken overseas.
Warner Bros. Pictures, the film's US distributor, briefly considered re-titling the film "Ranger" after test marketing showed that people didn't understand the original name. A handful of trade publications had the film listed as "Ranger" on their release schedules, but in the end WB decided to stick with "Spartan".
Many audiences became more familiar with the film after it's release on home video amidst the 2004 United States Presidential Campaign, due to Alexandra Kerry's supporting role as a bartender. Kerry's father, then-Massachussetts Senator John Kerry was running for President as the Democratic candidate.
When Scott's Arab informant is showing him information on the Dubai house (1'10'' into the movie), the Arabic information is an Arab newspaper article about the situation in Iraq in 2003 and UN envoy Segio Demelo.