A sheet discharge apparatus for a printer comprising a platen, a first discharge roller unit movable toward and away from the platen and defining a first sheet insertion passage at a location between the platen and the first discharge roller unit, an openable and closable top cover, a second discharge roller unit mounted for longitudinal movement in parallel relation to the top cover, to define a second sheet insertion passage at a location between the first discharge roller unit and the second discharge roller unit, and positioning means for the second discharge roller unit, which is provided on the printer body.