The Subaru XT is a 2+2 car manufactured and marketed by Subaru from 1985 till 1991, with a facelift in 1987. It is a two-door coupé with a front-mounted engine and either front-wheel drive or all-wheel drive. When the XT debuted, it was the most aerodynamic car in the US market.

Marketed as the Alcyone in Japan; as the Vortex in Australia and New Zealand; and as the XT (with the EA-82 four-cylinder engine) or XT6 (with the ER-27 six-cylinder engine) in North America and Europe, all XT cars were assembled at Subaru's Yajima Plant in Ota, Japan. Over its single generation, production reached just over 98,000.

The XT was conceived in the United States for the US market, and thus debuted globally in the US. After sales began in February 1985 in the US, the XT Turbo 4WD's debuted in Europe at the March 1985 Geneva Motor Show, followed by its Japanese debut in June 1985.

The XT was noted for its pronounced wedge shape, low coefficient of drag; aviation influences from the aircraft division of parent company Fuji Heavy Industry; and its host of features, either innovative or uncommon in the XT's class — including height-adjustable pneumatic suspension, digital dash, central locking system, op-art upholstery, fold down rear seat, pod- and center console-mounted HVAC controls, advanced trip computer, and instrument cluster which tilted with adjustment of the steering column. With available front-wheel drive or four-wheel drive, depending on the model year, the XT offered three trim levels, DL, GL (non-turbo, front-drive only), and GL-10 Turbo.

The Alcyone name was derived from Alcyone, the brightest star in the Pleiades star cluster, which is also included in the Subaru logo with some stylisation. The model was succeeded by the Subaru Alcyone SVX in 1992.

The XT featured a pronounced wedge shape, sharing a common "folded paper" design approach with the Type AA Subaru Leone. When introduced, the New York Times called it "the ultimate in jazzy design", in contrast to Subaru's other offerings. Though derived from earlier Subarus, it was less overtly practical or commodious. The 2.7-litre flat-six engine exceeded 2000 cc in the Japanese Domestic Market, thereby exceeding government engine displacement regulations, and incurring higher annual road tax.

The XT's exterior design team was led by Kiyoshi Sugimoto, with the interior team led by Hiroshi Yako, under the guidance of Tetsuya Hayashi. Some sources credit Kyuchi Akari with the final design, with notable inspiration from American designer Alex Tremulis, who had instructed Akari in aerodynamic principles and noted areas of possible flow separation.

Subaru's trademark boxer engine with its flat, horizontally opposed cylinder configuration, enabled the bodywork's pronounced wedge shape, and extensive wind tunnel testing further lowered the XT's coefficient of drag. Pop-up headlights contributed to the wedge shape, and retractable button-like flaps allowed opening the door while keeping the handles flush with their adjacent bodywork. The XT used a single 22 inch windshield wiper which tucked under the hood when not in use, and rubber spoilers ahead of each wheel opening settled the airflow past the tires and wheels, while doubling as "mud guards." The result was the most aerodynamic production car sold in America at the time of its release with a coefficient of drag of 0.29, improved fuel economy, and a quieter ride due to reduced wind noise.