A bidirectional delay circuit includes an input driving circuit and a delay switch circuit. The input driving circuit is connected between an input node and an intermediate node, and the input driving circuit amplifies an input signal received through the input node to generate an intermediate signal through the intermediate node. The delay switch circuit is connected between the intermediate node and a delay node, and the delay switch circuit delays both of rising edges and falling edges of the intermediate signal in response to a gate signal to generate a delay signal through the delay node. The gate signal may transition in response to the input signal.