Charles Henry "Charlie" Giancarlo (born 1957) is an American entrepreneur and investor.

[1] He joined Cisco in 1994 when it acquired Kalpana, an Ethernet switching company, where he was vice president.

[2] Giancarlo was responsible for many of Cisco's technologies including Ethernet switching, Wi-Fi, security, IP Telephony, and telepresence, as well as Cisco's entry into markets such as the small and medium business and consumer markets after acquiring Linksys, Scientific Atlanta, and WebEx.

[1][3] Although some analysts thought he might become chief executive after John T. Chambers, Giancarlo resigned from Cisco in December 2007.

After the appointment of Kevin J. Kennedy as CEO, he became chairman of the board at Avaya, while continuing to serve at Silver Lake[7][8][9] where he served on the boards of directors of Silver Lake portfolio companies Mercury Payment Systems, and Vantage Data Centers.