The former top military officer died on Monday morning, his family said.
He rose to become the first African-American secretary of state in 2001 under Republican President George W Bush.
Powell, who was fully vaccinated, later prompted controversy for his role in garnering support for the Iraq War.
“We have lost a remarkable and loving husband, father, grandfather and a great American,” the family said in a statement, thanking the staff at the Walter Reid Medical Center “for their caring treatment”.
As a four-star Army general, he was chairman of the military’s Joint Chiefs of Staff under President George H.W. Bush during the 1991 Gulf War in which U.S.-led forces expelled Iraqi troops from neighboring Kuwait.
In his remarkable decades-long career, Powell found it hard to live down his infamous speech to the United Nations Security Council, which paved the way for the Iraq invasion and ouster of Saddam Hussein. He had alleged the existence of weapons of mass destruction in Iraq, which turned out to be a false claim. The misleading intelligence input, resulting in the Iraq invasion, claimed hundreds of thousands of lives.
“It’s a blot… and will always be a part of my record. It was painful. It’s painful now,” Powell said in a 2005 interview with ABC News.
The former chairman of the Joint Chiefs of Staff was an American war hero who became the US secretary of state under the Bush administration. While announcing Powell’s appointment in 2000, then US President George W. Bush hailed him for his “towering integrity” and his “sense of duty and honour” as a soldier.
“In directness of speech, his towering integrity, his deep respect for our democracy, and his soldier’s sense of duty and honour, Colin Powell demonstrates… qualities that will make him a great representative of all the people of this country.”
Born April 5, 1937 in Harlem, Powell’s “American Journey” — the title of his autobiography — started in New York, where he grew up and earned a degree in geology.
He also participated in the Reserve Officers’ Training Corps (ROTC) in college, and upon his graduation in June 1958, he received a commission as a second lieutenant in the US Army, and was posted in what was then West Germany.
Powell completed two tours of duty in Vietnam — in 1962-63 as one of John F Kennedy’s thousands of military advisors, and again in 1968-69 to investigate the My Lai massacre.
He earned a Purple Heart, but also faced questions about the tone of his report into the hundreds of deaths at My Lai, which to some seemed to dismiss any claims of wrongdoing.
Back in Washington, he quickly rose through the ranks to the pinnacle of the national security establishment, serving Ronald Reagan as national security advisor, and both George H.W. Bush and Bill Clinton as chairman of the Joint Chiefs from 1989 to 1993.
Powell freely admitted his liberal social views made him a strange bedfellow for many Republicans, though the party was often happy to hold him up as an example of its inclusivity.
But since 2008, he has endorsed Democrats for the presidency, twice backing Barack Obama, and then Hillary Clinton and Joe Biden.
Powell earned a number of civilian honors, including the Presidential Medal of Freedom — twice from Bush Senior and Clinton.
He married his wife Alma in 1962. They had three children: Michael, Linda and Annemarie.
