Dimitri Alexandre Blaiddyd is a playable character in Fire Emblem Three Houses, as a member of the Blue Lions house. He is the hero in Azure Moon, a major antagonist in Crimson Flower, and a minor character in other routes. He is a human spear fighter with light skin and blonde hair. In all routes except Crimson Flower, Dimitri loses an eye and wears an eyepatch. He has a violent and volatile temper, and suffers from schizophrenia that manifests as hallucinating the ghosts of his dead loved ones. He was briefly step-siblings with Edelgard von Hresvelg when they were children, but in the present day he feels an intense enmity towards her, as he mistakenly blames her for the death of his family.

As the prince (and later king) of Faerghus, Dimitri is royalty.

Like the other house leaders, Dimitri develops a close friendship with Byleth and is one of their potential love interests. He will not marry a male Byleth, but fanworks have no such restriction.