Cisco Systems, Inc. (NASDAQ: CSCO) is an American multinational corporation headquartered in San Jose, California, United States, that designs, manufactures, and sells networking equipment. The stock was added to the Dow Jones Industrial Average on June 8, 2009, and is also included in the S&P 500 Index, the Russell 1000 Index, NASDAQ 100 Index and the Russell 1000 Growth Stock Index.

Len Bosack and Sandy Lerner, a married couple who worked as computer operations staff members at Stanford University, later joined by Erich Drafahl, founded Cisco Systems in 1984. Lerner briefly moved on to direct computer services at Schlumberger, but returned full time to Cisco in 1987.^{[citation needed]} The name "Cisco" was derived from the city name, San Francisco, which is why the company's engineers insisted on using the lower case "cisco" in the early days. For Cisco's first product, Bosack adapted multiple-protocol router software originally written some years before by William Yeager, another Stanford employee who later joined Sun Microsystems. The company's first CEO was Bill Graves, who held the position from 1987 to 1988. In 1988, John Morgridge was appointed CEO.