A time delay and integration or time delay integration (TDI) charge-coupled device (CCD) is an image sensor for capturing images of moving objects at low light levels. While using similar underlying CCD technology, in operation it contrasts with staring arrays and line scanned arrays. It works by synchronized mechanical and electronical scanning, so that the effects of dim imaging targets on the sensor can be integrated over longer periods of time.

TDI is more of an operating mode for CCDs than a separate type of CCD device altogether, even if technical optimizations for the mode are also available. The principle behind TDI—constructive interference between separate observations—is often applicable to other sensor technologies, so that it is comparable to any long term integrating mode of imaging, such as speckle imaging, adaptive optics, and especially long exposure astronomical observation.