The Honda Legend (ホンダ・レジェンド, Honda Rejendo) is a series of V6-engined executive cars that was produced by Honda between 1985 and 2021, and served as its flagship vehicle. The Legend has also been sold under the Acura Legend, RL and RLX nameplates — the successive flagship vehicles of Honda's luxury Acura division in North America from 1986 until 2020.

The first-generation Legend, introduced to Japan on October 22, 1985, was the first production Honda vehicle to offer only a SOHC V6 engine worldwide. The introduction of the Legend also coincided with the launch of a new dealership sales channel in Japan, called Honda Clio. The Legend was the result of a joint venture with Britain's Austin Rover Group called Project XX that started in November 1981 with the Austin Rover-Honda XX letter of intent signed by the two companies to replace the Rover SD1 and to provide a luxury vehicle for Honda, and was codenamed as HX. The Rover Company had a long-established reputation as a luxury car maker in the United Kingdom and Europe, demonstrated by the Rover P5 and Rover P6, and Honda wanted to introduce a luxury car for the Japanese, European and North American markets. Rover also wanted to return to the American market when previously they had reportedly sold only 1,500 cars in 1971, and a brief return in 1980, selling 800 Rover SD1s by offering the Sterling which was also a result of the ARG-Honda partnership. The development work was carried out at Rover's Canley, Coventry plant and Honda's Tochigi Prefecture development centre. Design work concluded on the Legend in 1982, with a design patent being filed on September 27, 1982, at the Japan Patent Office under application number 1982-043493 and registered on September 19, 1984, under patent number 0640105.

Honda and British Leyland/Rover agreed that Legends would be built at Cowley for the British market. However, few UK built Legends passed Honda's quality control standards, and many simply ended up being used as in-plant transport. In the end, only 4,409 Legends were built in the UK, from 1986 until 1988. All US-market Legends were built in Japan.

Honda wanted to expand its model range above the Honda Accord, and offer a premium level sedan that would appeal to wealthy middle-aged customers who were the traditional buyers of the Toyota Crown, Mazda Luce and Nissan Cedric/Gloria. In 1981, Honda had introduced a luxury level version of the Accord, called the Honda Vigor, but realized that they needed to manufacture a larger, more exclusive sedan with similar dimensions to the Crown, Luce, Cedric and Gloria. When the Legend was introduced worldwide, the optional equipment list was minimal as commonly identified equipment regarded as luxury in nature was included as standard equipment, leaving the only option the choice between a manual or automatic transmission.

The major mechanical difference between the Legend and the Toyota, Mazda and Nissan sedans was that the Legend was front-wheel drive, which Honda stated was "quite simply the most logical means to the ends the engineers desired: a true luxury car with a low, aerodynamic hood; a spacious interior with a nearly flat floor, and the superior traction that results from placing the engine and drivetrain transversely over the drive wheels." This provided the Legend with a front-end heavy 63/37 front to rear weight distribution ratio, similar to the NSU Ro 80. The ride was engineered to appeal towards the luxury car market and not necessarily towards the performance market, and the front to rear weight distribution ratio reflected this goal. Efforts to minimize torque steer were achieved by the half shafts and the angles of the joints at the ends of those shafts being equalized, helping the Legend to accelerate in a straight line.

The Japanese-spec Legend was offered in three trim levels; the V6Xi with the 2.5 L C25A V6 engine, with the slightly shorter and narrower V6Gi and V6Zi using the 2.0 L C20A V6. The V6Gi had the same level of equipment and luxury features as the V6Xi, whereas the V6Zi had reduced content and a lower price. The V6 engines were available with electronic, multi-port sequential fuel injection Honda called Programmed Fuel Injection, or PGM-FI and a variable length intake manifold on the smaller 2.0-liter V6. The larger 2.5 engine was upgraded to the C27A 2.7 liters of displacement for model year 1988 and added a variable length intake manifold. The engine benefited from Honda's successes with its endeavors in Formula One racing in 1964, and Honda's F1 racing car, the Honda RA271. Transmission selections were either a four-speed automatic transaxle with a computer controlled lockup torque converter, or a five-speed manual transaxle.

In order for the sedan to comply with Japanese vehicle size requirements and reduced tax liability, the car with the 2.0 L V6 was slightly shorter and narrower for Japanese buyers by reducing the extension of the front and rear bumper covers, and reducing the overall width to 1,695 mm (66.7 in). This also offered an alternative to the traditional Crown and Cedric/Gloria customer base due to the sedan being in the smaller size classification and reduced tax liability but with a comparable level of luxury equipment found in the larger cars, and the same amount of interior space due to the front-wheel drive powertrain, with a wheelbase advantage of 30 mm (1.2 in) over the Cedric/Gloria and Crown. To address the issue of durability, the Legend was manufactured as a pillared sedan instead of a four-door hardtop, a body style still offered at the time by Toyota and Nissan on the Crown and Cedric/Gloria. The slightly smaller body style also allowed the Legend to compete with the upscale Toyota Cresta and Chaser and the Nissan Laurel.

The Legend offered many Honda "firsts", such as a driver side airbag, vehicle speed sensitive power assist rack and pinon steering, anti-lock brakes, seat belt pre-tensioners with Emergency Locking Retractors (called E.L.R.), a choice of 100% wool or cloth moquette upholstery, and "TCS" Traction control, the first front-wheel drive car to use traction control. Attention was given to make sure the Legend was quiet, so Honda used computer simulation using NASTRAN, a stress analysis program created by NASA, helping the car achieve a drag coefficient of 0.32 and an interior noise level of 63 dB (measured while the vehicle was travelling at 100 km/h (62.1 mph) using a manual transmission in 5th gear), and by using triple seals around the tops of door openings.