Riza Hawkeye (リザ・ホークアイ, Riza Hōkai) is Roy Mustang's most trusted subordinate. She carries out many of the tasks he is too lazy to do, acts as his personal assistant, and protects him from danger. She also doubles as his voice of reason, keeping cool in heated situations and scolding him when he allows his emotions to get in the way. Riza and Roy seem to share a close relationship in both adaptions of Fullmetal Alchemist; in the anime she identifies him as her most precious person, whereas in the manga she loses her resolve to live when believing he has been killed. Riza specializes in firearms, particularly sniper rifles, and can hit nearly any target with lethal accuracy. She adopts a dog, called Black Hayate (ブラックハヤテ, Burakkuhayate), in both the anime and the manga, which she raises with stern discipline; when Hayate goes to the bathroom inside, she shoots at the wall behind him to reinforce that doing so is bad.
While Riza does not extend far past the role of Mustang's subordinate in the anime, she takes on a more central role in the manga. When Mustang begins to learn too much about the homunculi, Riza is reassigned as King Bradley assistant, a hostage to be used if Mustang steps out of line. Though she no longer works under Mustang, she still keeps an eye out for ways to make his plans of becoming Führer come true; she discovers that King Bradley's son, Selim Bradley, is a homunculus, and sends her discovery to him as soon as she can. She eventually defects from the military so that she can help Mustang overthrow King Bradley. Her back contains a tattoo consisting of all her father's alchemical research, so that it can never be forgotten. In the manga, there is a flashback after the Ishbalan War of her begging Roy to burn this tattoo away.