A fixing device includes: a fixing belt which is supported by one or more rollers; and a fixing roller which is in pressed contact with at least one of the rollers across the fixing belt, wherein the fixing roller includes a core portion which is rotatably provided, an elastic portion which covers the core portion so as to form a cylindrical shape with a rotation axis of the core portion being defined as a center, and a release portion which covers a cylindrical outer peripheral surface of the elastic portion, and an end of the elastic portion in a direction along the rotation axis and an end of the release portion in the direction along the rotation axis project from an end of the core portion, in the direction along the rotation axis, at a part where the core portion and the elastic portion are in contact with each other.