The list of ship commissionings in 1903 includes a chronological list of ships commissioned in 1903. In cases where no official commissioning ceremony was held, the date of service entry may be used instead.
The first USS Chauncey was a Bainbridge-class destroyer, also referred to as a "Torpedo-boat destroyer", in the United States Navy named for Commodore Isaac Chauncey. She was launched in 1901 and sunk in 1917.
USS Adder, later renamed A-2, was one of seven Plunger-class submarines built for the United States Navy (USN) in the first decade of the 20th century.
The O'Brien class of destroyers was a class of six ships designed by and built for the United States Navy shortly before the United States entered World War I. The O'Brien class was the third of five classes of destroyers that were known as the "thousand tonners", because they were the first U.S. destroyers over 1,000 long tons (1,016 t) displacement.
USS Nicholson was an O'Brien-class destroyer built for the United States Navy before the American entry into World War I. The ship was the second U.S. Navy vessel named in honor of five members of the Nicholson family who rendered distinguished service in the American Revolutionary War, the War of 1812, and the American Civil War: brothers James, Samuel, and John Nicholson; William Nicholson, son of John; and James W. Nicholson, grandson of Samuel.
USS Cushing was an O'Brien-class destroyer built for the United States Navy prior to the American entry into World War I. The ship was the second U.S. Navy vessel named in honor of William B. Cushing, a U.S. Navy officer best known for sinking the Confederate ironclad warship CSS Albemarle during the American Civil War.
The Japanese submarine I-31 was one of 20 Type B cruiser submarines of the B1 sub-class built for the Imperial Japanese Navy (IJN) during the 1940s.