自动调温器（英语、德语、法语: Thermostat），也可以称为温控器，这个设备可以用来控制系统提供的温度，使得系统温度一直保持在用户所想要温度点附近（因为控制的温度不可能精确地一直保持在固定的温度点，但是可以在温控器上设置恒温范围的大小数值）。用户利用调整设置来控制温控器，再经由温控器来管控外部系统的热能输出输入流量。也就是说，温控器利用开（ON）或关（OFF）控制暖气或冷气系统，来达到维持温度的目的。

可以用很多方法来设计温控器，也可以使用各种不同的感温组件来测量温度。感温组件的输出信号可以控制外置的暖气与冷气设备。

A thermostat is a component of which senses the temperature of a system so that the system's temperature is maintained near a desired setpoint. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature. Thermostats are used in any device or system that heats or cools to a setpoint temperature, examples include building heating, central heating, air conditioner, HVAC system, as well as kitchen equipment including ovens and refrigerators and medical and scientific incubators.