Hayden was commissioned through Duquesne University's Air Force Reserve Officers' Training Corps program,[7] and entered active military service in 1969.

The general served as director of the Joint Command and Control Warfare Center, at Lackland Air Force Base.

[8] Hayden was appointed as the director of the NSA and chief of the Central Security Service at Fort George G. Meade, Maryland from March 1999 to April 2005.

As the director of NSA and chief of CSS, he was responsible for a combat support agency of the Department of Defense with military and civilian personnel stationed worldwide.

Such omissions constituted a potential failure, subjecting the NSA to external critical feedback, including Diane S Roark, of the House Intelligence Committee.

NSA employees Thomas Andrews Drake, William Binney, and J. Kirk Wiebe voiced similar concerns.

On May 8, 2006, Hayden was nominated by President George W. Bush to be Director of the Central Intelligence Agency after the resignation of Porter J. Goss on May 5, 2006.

Hayden stated that he had relied upon legal advice from the White House, that warrantless surveillance would not have required a warrant from a FISA court.

The stated purpose of the database was to eavesdrop on international communications between persons within the U.S. and individuals and groups overseas in order to locate terrorists.

[19] Critics of the Hayden's nomination and his attempts to increase domestic surveillance included Senator Dianne Feinstein who stated on May 11, 2006, that "I happen to believe we are on our way to a major constitutional confrontation on Fourth Amendment guarantees of unreasonable search and seizure".

[20][21] In 2007, Hayden pushed to allow the CIA to conduct drone strikes purely on the behavior of ground vehicles, with no further evidence of connection to terrorism.

[28] In September 2013, Hayden stressed the indisputable legality of "what the NSA is doing" and called Edward Snowden a "troubled young man" and "morally arrogant to a tremendous degree".

He serves on the board of directors of the Atlantic Council,[31] and co-founded the Michael V. Hayden Center for Intelligence, Policy, and International Security.

[33] During his tenure as director, Hayden oversaw the controversial NSA surveillance of technological communications between persons in the United States and alleged foreign terrorist groups.

Trevor Timm, executive director of Freedom of the Press Foundation, accused the NSA program of mass surveillance set up during Hayden's tenure (including the vast database of Americans' domestic telephone calls) of violating FISA.

[34][35] In 2020, a federal court ruled that the NSA program of mass surveillance of Americans' telephone records was illegal and possibly unconstitutional.

[39] In response to a request made by future Secretary of State Antony Blinken, Hayden was one of the 51 former U.S. intelligence officials who signed an October 19, 2020, letter that said the Hunter Biden laptop story "has all the classic earmarks of a Russian information operation.

[41] Later, Hayden appeared to double down on his comments on Tuberville being "removed" from the human race, saying that "MAGAnuts had lost their mind" over his Twitter posts.

[50] In 2008, in his native Northside neighborhood, the city of Pittsburgh named a part of a street going past Heinz Field in his honor.