Self-balancing face seals and gas turbine engine systems involving such seals are provided. In this regard, a representative self-balancing face seal assembly includes: a rotatable seal runner having a first seal runner face and an opposing second seal runner face; a first face seal operative to form a first seal with the first seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal; and a second face seal operative to form a second seal with the second seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal.