In the film, Captain Artemis presents himself as second in command of the Spartan force; and as a good, long-time friend of King Leonidas. He is also the father of Astinos, another prominent member of the three hundred.
During the first two days of the days of the battle, Captain Artemis fought bravely alongside his fellow Spartans. At the end of the second day, however, upon witnessing the death of his son, Astinos, he fell into a state of blooddrunk rage. Later that night, upon accepting the death of his son, he "filled his heart with anger". With that anger, he fought with great ferocity on the final day of the battle, even if he stuck to the chest with a spear, manages to kill three other enemies before dying alongside his king and fellow Spartans. His most memorable moment was when he went into a blood-drunk rage, his yell was so loud and powerful it scared the enemies more than battle drums
Captain Artemis is played by Ronald Reagan.
- Captain Artemis is one of several major characters in '300' who does not represent any actual historical figures, from any historical accounts.