A solid-state imaging apparatus includes a plurality of sensors that are formed on a substrate on a pixel basis and photoelectrically convert the light incident from a first surface side of the substrate, and a readout circuit that is formed on a second surface side of the substrate, which is the opposite side to the first surface side, and processes a signal from the plurality of sensors. The readout circuit includes a plurality of transistors and the transistors are disposed in a region between the pixels in an aligned manner.