In May 1996, the Network Operations Center was established within the Command, Control, Communications, Computers, and Intelligence Directorate of Marine Corps Systems Command. It was subsequently renamed as the United States Marine Corps Network Operations Center (USMC NOC) in December 1997.
On 1 October 1999, the Marine Corps Computer and Telecommunications Activity and the USMC NOC were merged to form the Marine Corps Information Technology and Network Operations Center (MITNOC) under the control of the Director, Command, Control, Communications, and Computers Department, Headquarters, U.S. Marine Corps (HQMC C4).
On 1 July 2003, the Marine Corps Network Operations and Security Command (MCNOSC) was established under HQMC C4. Simultaneously, the MITNOC was deactivated, with its mission and personnel transferred to the MCNOSC.
On 30 October 2007, the MCNOSC was redesignated as the Marine Corps Network Operations and Security Center (MCNOSC).
On 1 October 2009, the U.S. Marine Corps Forces Cyberspace Command (MARFORCYBER) was activated and established as the Service Component to the U.S. Cyber Command. In accordance with this activation, the MCNOSC was realigned as a subordinate command under MARFORCYBER.
Effective 14 October 2016, the MCNOSC was redesignated as the Marine Corps Cyberspace Operations Group (MCCOG), as a subordinate operational force command to MARFORCYBER.
From June 2020 through February 2022, the MCCOG added the 1st, 2d and 3d Network Battalions, and Network Activities National Capitol Region, Europe/Africa and Reserves.
The MCCOG continues to execute Marine Corps Department of Defense Information Network Operations and Marine Corps Defensive Cyberspace Operations in order to enhance freedom of action across warfighting domains, while denying the efforts of adversaries to degrade or disrupt this advantage through cyberspace.