A leakage current-based delay circuit is provided, wherein the delay circuit may include a first transistor circuit and a second transistor circuit, each transistor circuit may include a p-type transistor, an n-type transistor, an n-node between a drain node of the p-type transistor and a gate node of the n-type transistor, and a p-node between a gate node of the p-type transistor and a drain node of the n-type transistor. The p-node of the second transistor circuit may be charged based on a power source voltage through the first transistor circuit during a first time interval of an input signal, and the n-node of the second transistor circuit may be discharged based on a ground voltage through the first transistor circuit during the first time interval.