A rotary potentiometer is an adjustable electrical resistor that can be moved by means of a rotary motion. This allows control processes to be implemented in various electrical or electronic systems, for example for volume control in multimedia devices.

A rotary potentiometer consists of three contacts, a carrier, and a circular resistor material. The two outer contacts are fixed and both are connected to the resistor. The third contact is movable and is known as a slider. In conventional designs, this can be rotated by up to 300 degrees via a rotary axis. By shifting the slider, the integrated resistance becomes either larger or smaller. This is how, for example, the voltages in a circuit can be variably controlled or exotic resistances can be generated.

With rotary potentiometers, a distinction is made between linear and logarithmic variants: a linear rotary potentiometer changes the resistance used analogously to the set angle of rotation. With a logarithmic rotary potentiometer, on the other hand, the value of the resistance initially changes less and increases proportionally with increasing rotary motion.