Mercury Cyclone is an automobile that was marketed by the Mercury division of Ford from 1964 to 1971. Introduced in 1964 as the Mercury Comet Cyclone, the Cyclone replaced the S-22 as the performance-oriented version of the Mercury Comet model line. The Cyclone became a distinct nameplate for the 1968 model year, as the Mercury Montegowas phased in to replace the Comet.
Within Mercury, the Cyclone was slotted between the Cougar pony car and the Marquis/Marauder full-size two-doors. Though largely overshadowed by the Cougar, the Cyclone was positioned as a muscle car, representing the Mercury brand in racing. 
Four generations of the Cyclone were produced, with production ending after the 1971 model year. For the 1972 model year, the Cyclone returned as an option package for the Montego; only 30 examples were produced. Within the Mercury line, the Cyclone was not directly replaced. The Cougar XR7 was repackaged as a personal luxury version of the Montego for 1974.
The Cyclone started as an option for the 1964 Mercury Comet. It featured a 289 cu in (4,736 cc), 210 hp (156.6 kW) engine and a sporty look. It had a spoked steering wheel and bucket seats. Some of the engine parts were chromed.In the 1965 models, the engine was updated to the four-barrel carbureted version of the 289 cu in (4,736 cc) unit, but generated 200 hp (149.1 kW). This model had a few performance options, which included a handling package, a special fan, and a "power transfer" rear axle. Special features included a black-out, stand-up grille, bucket seats with sewn-through pleats, center console, chrome-plated wheel covers with lug nuts, engine "dress up kit", unique insignias, a vinyl roof in black or white and a "Power-Pac" gauge cluster for the heavily padded instrument panel. The 1966 models underwent a major styling change. The body received "sculpturing" that ran the length of the car, and was based on the body of the Ford Fairlane. The models introduced new engines. The 390 Y code was a 390 cu in (6,391 cc) engine with a two-barrel carburetor and 265 hp (198 kW). The 390 H code had a four-barrel carburetor and 275 hp (205 kW).The GT option used a 390 S code engine which was a 390 cu in (6,391 cc) engine with a four-barrel carburetor and 335 hp (250 kW). The GT featured car stripes, a fiberglass hood (bonnet) with two air scoops and several other performance options.