Raytheon Company (NYSE: RTN) is a major American defense contractor and industrial corporation with core manufacturing concentrations in defense systems and defense and commercial electronics. It was previously involved in corporate and special-mission aircraft until early 2007. Raytheon is the world's largest producer of guided missiles.

Established in 1922, the company reincorporated in 1928 and adopted its present name in 1959. The company has around 73,000 employees worldwide and annual revenues of approximately US$20 billion. More than 90 percent of Raytheon's revenues were obtained from defense contracts and, as of 2007, it was the fifth largest defense contractor in the world, and is the fourth largest defense contractor in the United States by revenue.

Raytheon Headquarters was moved from Lexington, Massachusetts to Waltham, Massachusetts on October 27, 2003. The company was previously headquartered in Cambridge, Massachusetts from 1922–1928, Newton, Massachusetts from 1928–1941, Waltham from 1941–1961, Lexington from 1961–2003, and back to Waltham from 2003 onwards.