Unveiled at the 2011 New York International Auto Show, the fourth-generation Impreza (GJ sedan and GP hatchback) refined the compact vehicle's packaging by moving the A-pillars forward for enhanced interior space. Under the hood, it debuted Subaru's new FB-series engine family, primarily the FB20 2.0-liter and FB16 1.6-liter naturally aspirated flat-fours, mated to either a 5-speed manual or a Lineartronic CVT with Symmetrical AWD. The engineering setup effectively combined the low center of gravity inherent to the horizontally-opposed engine layout with a rigid chassis frame, delivering precise handling and composure across dry pavement and slippery surfaces alike. Engine bay packaging ensured optimal front-to-rear axle weight distribution alongside efficient thermal cooling under sustained driving loads.

A 2014 facelift updated the front end layout, side mirrors, and infotainment equipment, while a mild hybrid option (Impreza Sport Hybrid) was launched in select markets. Notably, starting from 2014, performance WRX and WRX STI models were officially separated into an independent line. Production of the fourth-generation Impreza ran until late 2016. Designers placed a strong emphasis on cabin ergonomics, occupant visibility, and long-distance driving comfort. Robust mechanical reliability across the drivetrain and suspension components helped establish this generation as a benchmark choice within its competitive market segment worldwide.