Leo Valdez is a fictional character from the children's book series The Heroes of Olympus by Rick Riordan.
Leo is the son of the Greek god Hephaestus and the mortal woman Esperanza Valdez. He has powers such as pyrokinesis and immunity to fire. He also learned building and engineering from his mother. He's also an exceptional builder and built The Argo II. Leo Valdez has attention deficit hyperactivity disorder and dyslexia.
Leo is 15 years old at the start of The Lost Hero, the first book in the Heroes of Olympus series. He is the best friend of Jason Grace and Piper McLean. He has called many different names throughout The Heroes of Olympus series such as, Chef Leo the Tofu Taco Expert, Admiral Leo, Super-sized McShizzle Man, Bad Boy Supreme, Supreme Commander of the Argo II, Flaming Valdez, Hot Stuff, and The Dread Pirate Valdez. At the end of Blood of Olympus he kills Gaea in a big fiery explosion, killing himself in the process. He gets revived from the physician cure .