数字电路或数字集成电路是由许多的逻辑门组成的复杂电路。与模拟电路相比，它主要进行数字信号的处理（即信号以0与1两个状态表示），因此抗干扰能力较强。数字集成电路有各种门电路、触发器以及由它们构成的各种组合逻辑电路和时序逻辑电路。一个数字系统一般由控制部件和运算部件组成，在时脉的驱动下，控制部件控制运算部件完成所要执行的动作。通过模拟数字转换器、数字模拟转换器，数字电路可以和模拟电路互相连接。

Digital electronics or digital (electronic) circuits are electronics that handle digital signals – discrete bands of analog levels – rather than by continuous ranges (as used in analogue electronics). All levels within a band of values represent the same numeric value. Because of this discretization, relatively small changes to the analog signal levels due to manufacturing tolerance, signal attenuation or parasitic noise do not leave the discrete envelope, and as a result are ignored by signal state sensing circuitry.