Introduced as the Agusta A119 Koala prior to the Agusta-Westland merger, it is targeted at operators favoring lower running costs of a single-engine aircraft over the redundancy of a twin.

The helicopter that was eventually to enter production as the A119 was conceived in 1994, as Agusta was recovering from a period of financial woes that had nearly put the company out of business.

[16][15][17] During summer 2015, it was reported that further delays to starting assembly in India were likely as the Foreign Investment Promotion Board (FIPB), an Indian government agency, repeatedly deferred a pending decision.

AgustaWestland promote the type as possessing excellent flight qualities with high levels of controllability, maneuverability and inherent safety.

[23][26] The AW119 Koala has been used for various roles, including utility, emergency medical services (EMS), offshore, law enforcement, and executive transport.

[2] The unobstructed cabin area and separate baggage compartment can be rapidly reconfigured to suit a range of different missions and roles.

[27] Initial production models featured conventional flight instruments;[27] the Garmin G1000 glass cockpit is integrated on the newer AW119Kx variant, which is claimed to improve situational awareness, reduce pilot workload, and increase safety.

[22] A variety of equipment can be equipped, dependent on operator choice and role; these include an external hoist, dual cargo hook, dual flight controls, baggage compartment extension, snow skis, windshield wipers, rotor brake, multi-band radios, active noise reduction headsets, soundproofing, oxygen systems, loud speakers, search lights, retractable landing light, emergency floatation equipment, reinforced windshield, wire strike protection system, rappelling kit, fire fighting belly tank, and a forward looking infrared (FLIR) camera.

[28][29] In February 2010, it was announced that AgustaWestland and Tata Group were to form a joint venture to produce the AW119 in India; the first Indian-manufactured units were originally planned to commence deliveries in 2011.

[30] In October 2015, following two years of deliberation, India's Foreign Investment Promotion Board approved a proposal to locally assemble the AW119Kx in Hyderabad, Telangana; the facility is to be operated by Indian Rotorcraft Ltd (IRL), the joint venture between AgustaWestland and Tata.

[33][34] In early 2015, AgustaWestland and Bristow Helicopters jointly offered an upgraded variant of the AW119 as a replacement for US Navy's existing fleet of 117 Bell TH-57 (based on the Bell 206) trainer helicopters under a fee-for-service contract; the companies claimed that over a four-year period the AW119 fleet could be introduced at an equal or lesser cost than that of continuing to operate the aging TH-57s.