Born in Fort Monroe, Virginia, he graduated West Point in 1917, and was commissioned a 2nd Lieutenant in the U.S. Army. After returning to West Point as an instructor in Spanish the year after he graduated, Ridgway completed the officers' course at the Infantry School in Fort Benning, Georgia, after which he was given command of the 15th Infantry. This was followed by a posting to Nicaragua, where he helped supervise free elections in 1927.
In 1930, he became an advisor to the Governor General of the Philippines. A few years later, he attended the Command and General Staff School in Fort Leavenworth, Kansas; at the same time (the mid-1930s), he was Assistant Chief of Staff of VI Corps. Thereafter, he held positions of Deputy Chief of Staff (2nd Army) and Assistant Chief of Staff (4th Army) of two army units. General George Marshall was impressed, and soon after the outbreak of World War II, he assigned Ridgway to the War Plans Division.
In August 1942, Ridgway was promoted to brigadier general, and was given command of the 82nd Airborne Division, one of the army's two airborne assault divisions. He helped plan the airborne invasion of Sicily, in 1943, and a year later, he helped plan the airborne operations on D-Day. In the Normandy operations, he jumped with his troops, which fought for 33 days in advancing to St-Sauveur-le-Vicomte. In September of 1944, Ridgway was given the command of the XVIII Airborne Corps, and led his troops into Germany. The year after, he was promoted to lieutenant general. At war's end, Ridgway was on a plane headed a new assignment under General of the Army Douglas McArthur, with whom he had served under while a captain at the United States Military Academy at West Point.
He held a command at Luzon for some time in 1945, before being given command of the US forces in the Mediterranean Theatre, also gaining the title of Deputy Supreme Allied Commander, Mediterranean. He was given command of US forces in the Caribbean in the late 1940s, before being given the position of Deputy Chief of Staff, under chief of staff General Joe L. Collins.
Ridgway's most important command assignment occured in 1950, upon the death of Lieutenant General Walton Walker. Upon Walker's death, he received command of the 8th US Army, which had been deployed in South Korea upon the invasion from North Korea in June of that year. He led his troops in a subsequent counter-offensive in 1951, and when General Douglas MacArthur was relieved of command by President Harry Truman, Ridgway was promoted to full general, assuming command of United Nations forces in Korea.
Military historians generally credit Ridgway with turning the 8th US Army from a defeated, broken army, into one that fought the overwhelming masses of troops from the People's Republic of China to a standstill. During this period, Ridgway's leadership by personal example, as well as his through knowledge of basic military operational principles, set a leadership standard few in US Army history could match. Ridgway also was not fazed by the Olympian demeanor of General McArthur, who gave Ridgway latitude in operations he had not given his predecessor.
In May 1952, Ridgway replaced General Dwight D. Eisenhower as the Supreme Allied Commander, Europe (SACEUR). However, he upset other European military leaders by surrounding himself with American staff, and returned to the U.S. to replace General Collins as the Chief of Staff of the United States Army. In that position, Ridgway is credited by historians as having delayed US entry into the Vietnam War, when President Eisenhower asked for his assessment of US military involvement in conjunction with the French. In response, Ridgway prepared a comprehensive outline of the massive commitment that would be necessary, which dissuaded the President from intervening. However, the experience sorely tested the relationship Ridgway had enjoyed during World War II with Eisenhower, and he retired from the US Army in 1955. Ridgway had been forced to retire earlier than he planned, but he was secure in the belief he had served his nation to the best of his ability. The year after his retirement, he published his autobiography, The Memoirs of Matthew B. Ridgway.
Ridgway's success in the military was not matched by success in his personal life. He married three times. For a while, he held the position of chairman of the board of trustees of the Mellon Institute for Industrial Research in Pittsburgh, Pennsylvania. According to his friends and colleagues, Ridgway was never the same after his son died in an auto accident in 1971, becoming increasingly depressed and morose. He died in March of 1993, holding permanent rank of general in the United States Army.