Miller was born in Waco, Texas, on October 12, 1919, Connery and Henrietta Miller. He was the third of four sons and helped around the house, cooking meals and doing laundry, as well as working on the family farm. Miller was a good student and was a fullback on the football team at Waco′s A.J. Moore Academy (5 ft 9 in (1.75 m), over 200 lb (91 kg)). He was called the "Raging Bull" because of his emotions. Large for his age, he was expelled from high school for fighting with students who insulted him for his race. On January 25, 1937 at age 17, he began the eight grade attending again. Forced to repeat the 8th grade the next year, Miller dropped out of school. He filled his time squirrel hunting with a .22 rifle and completed a correspondence course in taxidermy. He applied to join the Civilian Conservation Corps, but was not accepted. By now he was 6 feet 3 inches (1.91 m) tall and weighed more than 200 pounds (91 kg).
Miller worked on his father′s farm until just before his 20th birthday. On September 16, 1939, he enlisted in the United States Navy, where he became a Mess Attendant, Third Class, one of the few ratings then open to African Americans. Following training at the Naval Training Station, Norfolk, Virginia, he was assigned to the ammunition ship Pyro, but on January 2, 1940 was transferred to the battleship West Virginia, where he became the main cook. In July, he had temporary duty on the Nevada at Secondary Battery Gunnery School. He returned to his ship in August and was promoted to Ship's Cook, Third Class.
Miller's nickname "Dorie" apparently originated in a typographical error. After he was nominated for recognition for his actions on December 7, 1941, the Pittsburgh Courier released a story on March 14, 1942, that gave his name as "Dorie" Miller. Since then writers have suggested it was a "nickname to shipmates and friends."
He went instead to "Times Square", a central spot where the fore to aft and port to starboard passageways crossed, and reported himself available for other duty. Miller was spotted by Lieutenant Commander Doir C. Johnson, the ship's communications officer, who ordered the powerfully built sailor to accompany him to the bridge to assist with moving the ship's Captain Mervyn Bennion, who had a gaping wound in his abdomen where he had apparently been hit by shrapnel. Miller and another sailor lifted the skipper and, unable to remove him from the bridge, carried him from an exposed position on the damaged bridge to a sheltered spot behind the conning tower. The Captain refused to leave his post and questioned his officers about the condition of the ship, giving various orders. The Captain remained on the bridge until his death.
Lieutenant Frederic H. White ordered Miller to help him and Ensign Victor Delano load the unmanned #1 and #2 Browning .50 caliber anti-aircraft machine guns aft of the conning tower. Miller wasn't familiar with the machine gun, but White and Delano told him what to do. Miller had served both men as a room steward and knew them well. Delano expected Miller to feed ammunition to one gun, but his attention was diverted, and when he looked again Miller was firing one of the guns. White had loaded ammo into both guns and assigned Miller the starboard gun.
Miller fired the gun until he ran out of ammo, when he was ordered by Lieutenant Claude V. Ricketts along with Lt. White and Chief Signalman A.A. Siewart to help carry the Captain up to the navigation bridge out of the thick oily smoke generated by the many fires on and around the ship. Bennion was only partially conscious at this point and died soon after. Japanese aircraft eventually dropped two armor-piercing bombs through the deck of the battleship and launched five 18 in (460 mm) aircraft torpedoes into her port side. When the attack finally lessened, Lt. White ordered Miller to help move injured sailors through oil and water to the quarterdeck, thereby "unquestionably saving the lives of a number of people who might otherwise have been lost."
With the ship heavily damaged by the bombs, torpedoes and following explosions, the crew prevented her from capsizing by counter-flooding a number of compartments, and the West Virginia sank to the harbor bottom as her crew—including Miller—abandoned ship.
Miller was recognized as one of the "first heroes of World War II". He was commended in a letter signed by the Secretary of the Navy Frank Knox on April 1, 1942, and the next day CBS radio broadcast an episode of the series, "They Live Forever", which dramatized Miller's actions. On May 27, 1942 Miller was personally recognized by Admiral Chester W. Nimitz, Commander in Chief, Pacific Fleet, aboard the aircraft carrier Enterprise. Nimitz presented Miller with the Navy Cross, the third highest award for gallantry during combat that the Navy awarded at the time. Miller was cited for:
Nimitz told Miller, "This marks the first time in this conflict that such high tribute has been made in the Pacific Fleet to a member of his race and I'm sure that the future will see others similarly honored for brave acts." Negro organizations began a campaign to give Miller additional recognition. The All-Southern Negro Youth Conference on April 17-19, 1942 launched a signature campaign. On May 10, the National Negro Congress denounced the Secretary of the Navy, Frank Knox's recommendation against awarding Miller the Medal of Honor. However, on May 11, President Franklin D. Roosevelt approved the Navy Cross, the Navy's highest medal, for Miller. Miller was presented the Navy Cross on May 27, 1942.“...distinguished devotion to duty, extraordinary courage and disregard of his personal safety during the attack on the Fleet in Pearl Harbor on 7 December 1941. While at the side of his Captain on the bridge, Miller despite enemy strafing and bombing, and in the face of serious fire, assisted in moving his Captain, who had been mortally wounded, to a place of greater safety and later manned and operated a machine gun until ordered to leave the bridge.”