线性电压调节器（英语：Linear regulator），又称线性稳压器、线性调节器，是一种组件，作用是保持电压稳定。稳压器的电阻会因应负载及输入电压的变化，以达至输出电压稳定不变。其动作尤如一不停自动调节阻值的可变电阻，使之与负载得出的分压保持固定，而过程中因输出与输入电压差而多出的能量则以发热的形式消散掉。而开关式稳压器是不停高速地在导通/断开之间切换，使得输出的平均值保持在所需电压值。输入线性稳压器的电压必须高于输出电压，好让稳压器内能作出降压作用以达至输出稳定，因此效率受限制。

线性稳压器可以是置于电源和负载之间（串联稳压器），或与负载并联（并联稳压器）。简单的线性稳压器可以只包含齐纳二极管和一枚串联电阻器；更复杂的线性稳压器包含多个组成部份：参考电压、误差放大器和功率传输组件。由于线性稳压器被广泛应用，因此多被制成集成电路，但也可以固态电子器件或真空管等分立组件构成。

In electronics, a linear regulator is a system used to maintain a steady voltage. The resistance of the regulator varies in accordance with the load resulting in a constant output voltage. The regulating device is made to act like a variable resistor, continuously adjusting a voltage divider network to maintain a constant output voltage, and continually dissipating the difference between the input and regulated voltages as waste heat. By contrast, a switching regulator uses an active device that switches on and off to maintain an average value of output. Because the regulated voltage of a linear regulator must always be lower than input voltage, efficiency is limited and the input voltage must be high enough to always allow the active device to drop some voltage.