在电子学中，共漏极（英语：common-drain）放大器电路，是场效应管（field effect transistor (FET)）三种基本接法之一（另外两种分别是共源极和共栅极），常被用作电压跟随器。这种电路的栅极被用作输入端，源极充当输出端，而漏极作为公共端，电路因此得名。在双极性晶体管中，类似的概念称作共集极。

In electronics, a common-drain amplifier, also known as a source follower, is one of three basic single-stage field effect transistor (FET) amplifier topologies, typically used as a voltage buffer. In this circuit (NMOS) the gate terminal of the transistor serves as the input, the source is the output, and the drain is common to both (input and output), hence its name. The analogous bipolar junction transistor circuit is the common-collector amplifier. This circuit is also commonly called a "stabilizer."