On 20 June 2011, development of the eight-tonne twin-engine AW189 was formally announced by AgustaWestland at the Paris International Air Show; at the time, the company planned to have the new rotorcraft certified by 2013 and in service in 2014.

[2] The AW189 is a civil-orientated version of the military AW149, which in turn is an enlarged development of the AW139; in 2011, AgustaWestland CEO Bruno Spagnolini stated that: "The AW139 and the AW189 are two very different aircraft but they both share the same general concept in architecture".

[3] AgustaWestland stated it aimed to sell the AW189 for offshore helicopter support, search and rescue (SAR), and passenger transport roles.

[8] The pre-production aircraft were used to develop mission kits and configurations for offshore and SAR roles, enabling these to be immediately certified and available for customer selection.

EASA certification for the AW189K was initially expected in late 2018[17] this was eventually achieved in June 2020;[18] hot and high operations would benefit from the additional 500shp (370 kW) per engine and the Aneto's specific fuel consumption was planned to be 10% lower than the replaced CT7s.

[12][21] Of particular importance to the type's use for offshore operations, such as search and rescue and services to the oil and gas industries, the main gearbox has been designed to provide for a 50-minute run-dry capacity, in excess of requirements and a unique feature to the AW189.

[12][21] The cockpit features high levels of external visibility and advanced situational awareness technologies, and is designed to reduce crew workload and enhance safety.

[21] The interior is customised to the mission role being undertaken; these include a self-contained emergency medical service (EMS) layout, passenger configurations (with in-flight entertainment systems offered), mission consoles for SAR and law enforcement operations, and an optional dividing wall between the cockpit and main cabin may also be installed.

[5] Various pieces of optional equipment can be installed upon the AW189, including fast roping kits, external electric hoist, cargo hook, air conditioning, auxiliary fuel tanks, mission console, emergency flotation system (certified up to Sea State 6), external life rafts, emergency lighting, external search light, main cabin bubble windows, wire strike protection system, de-icing systems providing multiple levels of protection.

Two AW189s will conduct SAR duties on behalf of British Forces garrisoned at Mount Pleasant Airfield on the South Atlantic islands, replacing RAF Sea Kings that will be retired at the end of March 2016.