A motor unit includes: a first rotating electric machine which includes a cylindrical first stator, a first rotor disposed coaxially with the first stator, a first shaft disposed coaxially with the first rotor, and a cylindrical first casing accommodating the first stator and the first rotor; a second rotating electric machine which includes a cylindrical second stator, a second rotor disposed coaxially with the second stator, a second shaft disposed coaxially with the second rotor, and a cylindrical second casing accommodating the second stator and the second rotor; a single drive device which is integrally fixed across a peripheral surface in a diameter direction of the first rotor in the first casing and a peripheral surface in a diameter direction of the second rotor in the second casing; and a surface-matching fixing portion which is fixed by a fixing member while an axial end surface of the first casing comes into contact with an axial end surface of the second casing.