The fourth-generation Honda Integra (chassis code DC5), produced by Honda, was introduced in Japan on 13 April 2001 and produced from July 2001 until August 2006. It was introduced in North America on 2 July 2001 as the Acura RSX, the name a part of Acura's naming scheme changing the names of its models from recognizable names like "Integra" or "Legend" to alphabetical designations in order for buyers to build more recognition to the marque, and not the individual cars.

In concordance with the introduction of the Integra's platform mate, the seventh-generation Civic being introduced in 2000, the Integra joined the Civic in abandoning Honda's traditional double wishbone suspension at both ends and adopted MacPherson struts in the front and trailing arm type suspension in the rear along with the new K-series engine supplanting the B-series.

The K-series engine features intelligent VTEC (or i-VTEC), which electronically adjusts valve lift and duration between separate cam profiles, as well as valve timing with the implementation of a continuously variable sprocket, giving the 2.0 L engine a flatter torque curve relative to previous VTEC implementations which only adjusted valve lift and valve duration.

The Integra received a facelift in 2004. The headlight and taillight assemblies lost the "half circle" on the bottom. This made the assemblies flush with the bumpers. The interior received new trim and gauge clusters, an immobilizer and alarm became standard, the body became stiffer, the suspension springs were redesigned, and the car's tendency to bump steer was reduced.

In Japan, the Integra was introduced in two versions, the iS (later renamed Type S in the 2004 refresh) and the Type R.

The iS/Type S (not to be confused with the RSX Type-S), featured the 2.0L DOHC i-VTEC 4-cylinder K20A3 engine with an output of 160 hp (120 kW) and mated to either a 5-speed automatic or a 5-speed manual transmission. The 2001–2003 iS was available with 15-inch steel wheels with covers, or optional 16-inch 5-spoke alloy wheels. The 2004–2006 Type S was equipped with 17-inch 5-spoke alloy wheels shared with the RSX Type-S. The JDM Type R had reduced weight, a 2.0L DOHC i-VTEC 4-cylinder K20A engine that output 217 hp (164 kw)  (Japan-only; Oceania models use an engine similar to the RSX Type-S), 6-speed close-ratio manual transmission, as well as a helical limited-slip differential (LSD), stiffer springs and shocks, high intensity discharge (HID) bulbs paired with specially designed reflector headlights (different from all other RSX models), aluminum pedal set, 4-piston front Brembo brake calipers, 17-inch 5 double-spoke wheels on Bridgestone Potenza tires, Recaro faux suede seats/matching interior, leather-wrapped MOMO steering wheel, body trim, front strut bar, and more. The Type R lacked many of the luxury features (like vanity mirrors or side airbags) found in the Type S, true to its racing heritage. The C package on the Type R added various accessories, such as a rear wiper, remote control, and folding mirrors. The JDM iS had one interior color, Ebony, in its first year. After 2002, Titanium interiors became available for all exterior colors. The Type S had redesigned cloth and leather seats. The Type R had choices of black/blue/red interiors (including color matching Recaro seats), depending on exterior colors. The refreshed Type R had the option of either the high wing, or the trunk lip spoiler. Both the iS and Type S were available with sunroof, and navigation systems. Additional interior and exterior accessories were available from Honda's Modulo line. Modulo accessories offered include interior trim (shift knobs, decals, etc.), foglights, aero kits (front/side/rear bumper enhancements), wing spoilers, alloy wheels, push button start, upgraded speakers, and navigation.

Japan's vehicle parts road compliance regulations means many tuning parts for the Integra can be purchased from Honda dealerships. For example, M&M Honda, a Honda dealer, manages their own brand of parts. Honda tuner Mugen sells their performance parts via Honda dealers as accessories.

In Australia, the Integra was available in four models: the base model, simply named Integra, Luxury, Type R and Type S. The base Integra was simply the Japanese-market iS, while the Luxury added accessories like leather seats and a sunroof. Australian Type Rs were different from the JDM models, as they were not equipped with all of the features of the latter. They lacked the Brembo braking system, used the 200 hp K20A2 in place of the slightly more powerful K20A, and regular 16-inch 5-spoke wheels, painted in gun metal or white, were used instead of the 17-inch, 5 dual-spokes. However, the Australian Type R does retain the JDM model's helical limited-slip differential, and full Type R interior (MOMO steering wheel, aluminum pedals and shift knob, Recaro seats and color matched carpets) and aero (wing and front/rear bumper lips). The Type R was dropped in 2004, and replaced by the Type-S, which was mechanically identical to the USDM RSX Type-S (though it did lack cruise control), but badged like the JDM Type-S. With the Integra's refresh in 2004, the base model was dropped. The only trims available in 2006 was the Luxury and Type-S. Black was the only interior color available for the redesign. For facelifted Oceanic models, extra strengthening was given to fit higher safety regulations.