An image noise reduction circuit includes an image correction portion which is responsive to a timing pulse signal to reduce a noise in an input image signal based on a difference data and to generate a corresponding output image signal, a difference detecting portion which generates the difference data corresponding to a difference between a first image data and a second image data where the first image data is contained in the input image signal and the second image data is contained in a preceding output image signal generated by the image correction portion, and a pulse generating portion which generates the timing pulse signal at a vertical blanking interval of the input image signal.