Provided is a signal processing apparatus, including: an A/D conversion unit configured to perform A/D conversion of a first signal, A/D conversion of a second signal, A/D conversion of a third signal, and A/D conversion of a fourth signal; and a correlated double sampling processing unit configured to generate a first output signal by performing correlated double sampling using a first digital data item obtained through the A/D conversion of the first signal, and a second digital data item obtained through the A/D conversion of the second signal, a second output signal by performing correlated double sampling using a third digital data item obtained through the A/D conversion of the third signal, and a fourth digital data item obtained through the A/D conversion of the fourth signal, and a third output signal by performing correlated double sampling using the first output signal and the second output signal.