The Acura ARX-05 is a Daytona Prototype International (DPi) sports prototype racing car developed by Honda Performance Development (HPD) in collaboration with Oreca. The car began use in 2018 and was designed in accordance with DPi regulations debuted by the International Motor Sports Association (IMSA) the year prior, based on the LMP2 chassis by Oreca 07. The ARX-05 first competed in the IMSA Weathertech Sportscar Championship in a factory-backed effort with Team Penske before being raced by customer teams Wayne Taylor Racing and Meyer Shank Racing.

The ARX-05 marked Acura's return to competition in North American prototype racing following previous programs under the HPD name. In its five seasons of competition from 2018 to 2022, the ARX-05 would find consistent success in IMSA competition, being a regular fixture in championship fights and winning a number of races.

With DPi regulations replaced by the Le Mans Daytona h (LMDh) regulations from 2023 onwards, the ARX-05 was retired and replaced by the Acura ARX-06.

Honda Performance Development's previous efforts in IMSA prototype competition had ended under difficult circumstances. In the 2014 season, the ARX-03, a predecessor to the ARX-05, was withdrawn from later races by Extreme Speed Motorsports due to complaints regarding IMSA's balance of performance requirements.

By the 2015 season, with Extreme Speed Motorsports reducing its IMSA campaign to endurance events only, the participation of HPD's newly developed ARX-04b was similarly limited. The ARX-04b proved to be a significant failure, competing only in the 2015 24 Hours of Daytona before being shelved for the older ARX-03, which itself would compete in only one more IMSA race before Extreme Speed Motorsports cancelled the remainder of its 2015 campaign. The ARX-04b would not compete again despite continued development and testing.

Hoping to move on from previous setbacks, Honda began preparations for its next IMSA prototype as new regulations for LMP2 prototypes for 2017 were finalized alongside IMSA's DPi ruleset. HPD conducted multiple interviews with multiple different chassis manufacturers before ultimately reaching an agreement with Oreca to use the Oreca 07 as the basis for the ARX-05, which, for the first time since 2011, would be branded as an Acura. HPD and Acura's design team worked in tandem to develop the car.

Acura's return to IMSA prototype competition was formally announced on July 11, 2017, with HPD having reached an agreement with Team Penske to campaign the car from the 2018 season onwards. The ARX-05 was publicly unveiled at Laguna Seca on August 18, 2017.

The ARX-05 is constructed around the Oreca 07's carbon-fiber monocoque chassis. Acura-specific bodywork and exterior styling were developed by Acura Design Studio in California in collaboration with HPD and Oreca engineers. The car incorporates Acura's signature "Jewel Eye" headlight styling from their production cars while retaining the standardized cockpit dimensions and survival cell structure mandated by the new LMP2 regulations for all DPi entries.