The INEOS Grenadier was created by British billionaire Sir Jim Ratcliffe, chairman of chemical giant INEOS. In 2017, Ratcliffe approached Land Rover to buy the rights to produce the old Defender, but was refused. Instead, he founded INEOS Automotive and decided to build his own "proper 4x4". The Grenadier's boxy, utilitarian design intentionally echoes the classic Defender, featuring a stepped bonnet, round headlights, black plastic wheel arches, and a rear-mounted spare tyre. The vehicle's name comes from the London pub where Ratcliffe first envisioned the project.

The INEOS Grenadier is powered by a 3.0-litre turbocharged inline-six petrol engine sourced from BMW, producing 286 PS (282 hp) at 4,750 rpm and 450 Nm of torque from 1,750 to 4,000 rpm. It is paired with an 8-speed automatic transmission and features a full-time four-wheel drive system with low-range gearing and differential locks.

The Grenadier is designed for serious off-road use with exceptional capability. It features generous wheel articulation and suspension travel, an 800 mm wading depth, and a low-range transfer case. The overhead control panel provides easy access to various driving modes, differential locking systems, and low-range gearing. Testing in challenging conditions including rock crawling, sand dunes, and water crossings has demonstrated its ability to handle the world's harshest environments.

The INEOS Grenadier is a 5-door, 5-seater mid-size SUV. With the second-row seats folded down, it offers up to 2,035 litres of cargo space, sufficient for luggage and bulky items. The vehicle also features a Rhino Roof Rack option with a static load capacity of 420 kg and a dynamic load limit of 150 kg, allowing a roof tent to be mounted.