A signal processing device includes an acquisition unit configured to acquire a first shake detection signal indicating a detection result of a lens shake detection unit included in an interchangeable lens and a second shake detection signal indicating a detection result of a camera shake detection unit included in a body unit and a determination unit configured to determine a correction amount which is used to correct the first shake detection signal based on the first shake detection signal and the second shake detection signal. The determination unit changes a process parameter for determining the correction amount in accordance with information regarding the camera shake detection unit or information regarding the second shake detection signal. The process parameter includes at least one of a restriction frequency and a gain for the correction amount.