In a sheet conveyance apparatus a control unit controls lifting and lowering of a sheet supporting portion by a lifting unit and executes a mixed feeding in one of a plurality of modes including a first mode and a second mode. The mixed feeding is an operation in which a plurality of sheets having different lengths in a width direction orthogonal to a feed direction of a sheet feeding unit are fed by the feeding unit, wherein in the first mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on an instruction to start sheet feeding, and in the second mode, the control unit causes the lifting unit to move the supporting portion from the second position to the first position based on a detection of a sheet by the detection unit.