Combustion Engineering was a leading firm in the development of power systems in the United States in the late 20th century. The firm was purchased by Asea Brown Boveri in the mid-1990s. It is now owned by Westinghouse Electric Company.

Combustion Engineering (C-E) designed and built boilers for conventional power plants - those powered by coal and oil. In the 1960's, C-E began selling nuclear power steam supply systems. The first commercial nuclear steam supply system was sold to Consumers Power Company of Michigan for the Palisades Nuclear Plant, which is still in operation. C-E competed aggressively with General Electric and Westinghouse in this domain. C-E was generally credited with a superior design, evidenced by the fact that the megawatt yield of its reactors was typically about 10% higher than that of comparable Westinghouse plants. The basis for this increase in efficiency was a computer-based system called the Core Operating Limit Supervisory System (COLSS), which leveraged almost 300 in-core neutron detectors and a patented algorithm to allow higher power densities.

C-E was an innovative American engineering firm with approximately 10,000 employees in about a dozen states. Headquartered in Windsor, Connecticut, it had a major boiler manufacturing facility in Chattanooga, Tennessee. Alumni from C-E have gone on to hold leadership positions in major engineering firms and governments around the world.