Automation is a technology that performs a process or a procedure with a minimum of human assistance. Automation or automatic control refers to the use of various control systems for operating equipment such as machinery, factory processes, boilers and heat treatment furnaces, switching on the telephone network, ships, aircraft, and other applications of steering and stability, and vehicles with little or no human intervention. Some processes are completely automated.
Automation includes a wide range of applications, from a home thermostat that controls a boiler to large industrial control systems that have tens of thousands of input measurements and output control signals. In terms of controlling complexity, it can range from simple switch controls to multivariable high-order algorithms.

In a simple type of automatic control loop, the controller compares the measured value of the process with the desired set value and processes the resulting error signal to change some of the inputs to the process, so that the process remains at its set point in the presence of disturbances. This closed-loop control is an application of negative feedback in the system. The mathematical foundation of control theory began in the 18th century and developed rapidly in the 20th century.

Automation is achieved by various means, including machinery, hydraulics, pneumatics, electronics, and computers, which are often combined. Complex systems such as modern factories, aircraft, and ships usually make use of all these combined technologies. The benefits of automation include saving on labor, saving on electricity costs, saving on material costs, and improving quality, accuracy, and precision.

The World Bank's "World Development Report 2019" shows that while automation is replacing workers, innovation is creating new industries and jobs.

The term automation was inspired by the early automation (from automaton), and was not in widespread use before the establishment of Ford's Automation Department in 1947. It was during this period that the industry rapidly adopted the feedback controller, which was introduced in the 1930s.