A clock signal delay circuit includes a variable delay unit, a delay unit, a phase detection block, a control clock output block, and a delay control unit. The variable delay unit controls a delay amount of a reference clock signal based on a delay control signal and provides a delayed clock signal based thereon. The delay unit delays the delayed clock signal and provides a feedback clock signal based thereon. The phase detection block detects a phase difference between the feedback clock signal and the reference clock signal and provides a detected phase difference based thereon. The control clock output block provides a control clock signal based on the detected phase difference. The delay control unit generates the delay control signal based on the detected phase difference and in response to the control clock signal.