The V-boats were a group of nine United States Navy submarines built between World War I and World War II from 1921 to 1934 under authorization as the "fleet boat" program.

The term "V-boats" as used includes five separate classes of submarines: large, fast fleet submarines (V-1 through V-3), large long-range submarines (the minelayer V-4 and two submarine cruisers V-5 and V-6) and three medium-sized submarines (V-7 through V-9).

The successful fleet submarines of World War II (Tambor class through Tench class) were descended from the last three, especially V-7, though somewhat larger with pure diesel-electric propulsion systems.

Originally called USS V-1 through V-9 (SS-163 through SS-171), in 1931 the nine submarines were renamed Barracuda, Bass, Bonita, Argonaut, Narwhal, Nautilus, Dolphin, Cachalot, and Cuttlefish, respectively. All served in World War II, six of them on war patrols in the central Pacific. Argonaut was lost to enemy action.

In the early 1910s, only 12 years after Holland inaugurated the Navy's undersea force, naval strategists had already begun to wish for submarines that could operate in closer collaboration with the surface fleet than the Navy's existing classes, which had been designed primarily for coastal defense. These notional "fleet" submarines would necessarily be larger and better armed, but primarily, they would need a surface speed of some 21 kn (24 mph; 39 km/h) to be able to maneuver with the 21-knot battleships around which the battle fleet was built. This was the designed speed of the Delaware class and later battleships, including the standard-type battleships that were under construction and proposed in 1913.

In the summer of 1913, Electric Boat's chief naval architect, former naval constructor Lawrence Y. Spear, proposed two preliminary fleet-boat designs for consideration in the Navy's 1914 program. In the ensuing authorization of eight submarines, Congress specified that one should "be of a seagoing type to have a surface speed of not less than twenty knots". This first fleet boat, laid down in June 1916, was named USS Schley after Spanish–American War hero Winfield Scott Schley. With a displacement of 1,106 long tons (1,124 t) surfaced, 1,487 long tons (1,511 t) submerged, on a length of 270 ft (82 m), Schley (later AA-1, and finally T-1) was twice as large as any previous U.S. submarine. To achieve the required surface speed, two tandem 1,000 hp (750 kW) diesel engines on each shaft drove twin screws, and a separate diesel generator was provided for charging batteries. Although Schley and two sisters authorized in 1915—USS T-2 (SS-60) (originally AA-2), and USS T-3 (SS-61) (originally AA-3)—all made their design speed of 20 kn (23 mph; 37 km/h), insoluble torsional vibration problems with their tandem engines made them very troublesome ships, and they were decommissioned in 1922-1923 after a service life of only a few years. As the engines were clutched together, perfectly synchronizing operation of the engines was impossible.

In 1916, well before the T class debacle transpired, Congress authorized 58 coastal submarines and nine additional "fleet" boats. Three of the larger 800 long tons (813 t) coastal boats eventually became competing prototypes for the long-lived, 51-member S class. The nine "fleet boats" became the "V-boats", built between 1921 and 1934, and in fact, they were the only U.S. submarines produced in that period. Although V-4, V-5, and V-6 were the largest US non-nuclear submarines ever built, only V-1 through V-3 were designed to reach a speed of 21 knots.

The first three V-boats were funded in fiscal year 1919, laid down at the Portsmouth Navy Yard in October and November 1921, and commissioned somewhat less than a year apart between 1924 and 1926. Significantly, V-1, V-2, and V-3 were the only members of the class designed to satisfy the Navy's original "fleet boat" requirement for high surface speed. These were large and powerfully engined submarines, displacing 2,119 long tons (2,153 t) surfaced and 2,506 long tons (2,546 t) submerged on a length of 342 ft (104 m). The propulsion plant was divided between two separate engine rooms—forward and aft of the control room—with two 2,250 hp (1,680 kW) main-propulsion direct-drive diesels aft, and two independent 1,000 hp (750 kW) diesel generators forward. The latter were primarily for charging batteries, but to reach maximum surface speed, they could augment the mechanically coupled main-propulsion engines by driving the 1,200 hp (890 kW) electric motors in parallel. This partial diesel-electric propulsion system foreshadowed the later successful all-diesel-electric submarines, although nearly 10 years of development were required before it was reliable. The three boats were partially double-hulled and fitted forward with buoyancy tanks inside a bulbous bow for better surface sea-keeping. They were armed with six 21-inch (533 mm) torpedo tubes, four forward and two aft with 12 torpedoes, plus a 5-inch (127 mm)/51 caliber deck gun.