The HU-1A (later redesignated the UH-1 Iroquois) was the first turbine-equipped U.S. helicopter to go into production, and production models first entered service with the 101st Airborne at Fort Lewis, Washington. Although they were intended for evaluation only, the Army quickly pressed them into operational service.

The helicopter was originally designated the HU-1A, which is where it received its nickname - "Huey." The official U.S. Army designation Iroquois (Army helicopters are traditionally given Native American names) was almost never used in practice. The HU-1B was equipped with revised main rotor blades and could carry seven passengers. These versions were redesignated UH-1A and UH-1B respectively, in 1962. A UH-1C gunship version with a more powerful engine was later built, along with search and rescue (SAR) and training variants.