Ford-O-Matic was the first automatic transmission widely used by Ford Motor Company. It was designed by the Warner Gear division of Borg-Warner Corporation and introduced in 1951 model year cars, and was called the Merc-O-Matic-named when installed in Mercury-branded cars and Turbo-Drive when installed in Lincoln-branded cars. In contrast to Detroit Gear Division's three-band automatic originally designed for Studebaker, which became superseded by this unit, a variation of Warner Gear's three-speed unit named Ford-O-Matic continued to evolve later into Cruise-O-Matic transmissions in 1958 and finally the FMX-named transmissions in 1968. This line continued in production until 1980, when the AOD was introduced. Like Ford, variations of this same Borg-Warner design were used by other automobile manufacturers, as well, such as AMC, International Harvester, Studebaker, Volvo, and Jaguar, each of them having the necessary unique adaptations required for the individual applications.

In 1948, Ford realized it was late in introducing a fully automatic transmission to its automobile lineup. Ford initially approached Studebaker to purchase rights to use the DG-series automatic developed by the Detroit Gear division of Borg-Warner. The Studebaker board of directors was agreeable, but stipulated that Studebaker would have one-year exclusive use of the design before Ford could use it. Since the DG was available in Studebaker cars in mid-1950, this meant that Ford would have to wait until mid-1951 to introduce an automatic. The wait was unacceptable, so Ford went a different direction.

Ford Engineering Vice President Harold Youngren, recently hired away from Borg-Warner, recommended that Ford license and build a transmission using a design he was working on at his previous employer. Ford and the Warner Gear division of Borg-Warner signed a contract in 1948 which entered B-W into a supply agreement wherein they would build half of Ford's transmissions for five years, with the other half either being built by Ford or by a different supplier. Because of this agreement, Ford licensed the design and broke ground immediately on an assembly plant to build the remaining transmissions. The new Fairfax Transmission Plant was dedicated in 1950.

The original Ford-O-Matic accomplished two things that Ford's two previous automatic transmissions failed to do: Through the use of an integrated torque converter and planetary gearset, Ford's automatic shifted smoothly without an interruption in torque from the engine. The other was the shifting pattern, revised from PNDLR to PRNDL, which served to reduce "shift shock" when changing gears and reduce "torque shock" when trying to rock a stuck car back and forth.

The original Ford-O-Matic, while capable of three forward speeds, started out in second and shifted to third, with first only being used when selecting L on the gear shift column. However, if floored from a standing start, it would immediately shift from second to low, then shift back to second and then third as the vehicle accelerated.

The Ford-O-Matic was manufactured from 1951 until it was replaced by the C4 in 1964. Ultimately, the transmission Ford licensed to build from Warner Gear/B-W was less expensive to build than the Detroit Gear/B-W unit that Ford had initially sought to license from Studebaker. When Studebaker ran into financial difficulty in the mid-1950s, Studebaker turned to Ford and licensed the less expensive Ford-O-Matic, rebranded it as the Flight-O-Matic, and dropped the DG transmission from its line-up.

For 1957, Mercury offered mechanically activated pushbutton transmission controls in response to the Chrysler TorqueFlite pushbutton controls introduced in 1956. The Mercury control buttons initially offered five buttons and was called "Keyboard Control", with a long button on top labeled "Drive", with four smaller buttons below labeled "Brake", "Neutral Start", which would allow the engine to start with the ignition key, "Hill Control", and "Reverse", with later versions separating the "Drive" button to "Performance" and "Cruising" for 1958 and relabeled as "Multi-Drive Keyboard Control". A separate push/pull lever was included below the control buttons labeled "Park", which would lock out the control buttons until the Park button was pulled to release it. The control panel was installed to the left of the steering wheel. In 1959, the keyboard control was discontinued, replaced by a steering column gear-selector lever.

In the mid-1950s, cars began to grow in size, and in response to heavier vehicles, more powerful engines were being developed. The original Ford-O-Matic was used as a template when developing the next automatic transmissions for Ford; in fact, many of the gear sets are interchangeable. The new transmissions arrived for model year 1958, which coincided with the release of Ford's new FE and MEL engines. Although marketed as Cruise-O-Matic, the new transmissions were known internally as the MX (larger) and the FX (smaller). They were a three-speed design using a Ravigneaux planetary gearset like the original, but moved the pump from the rear to the front of the transmission, while also using a different valve body so the transmission would start in first gear as opposed to second. The MX was built in the Livonia Transmission Plant in Livonia, Michigan, and was placed behind the more powerful engines in Mercury, Lincoln, and select Ford models. The smaller FX was built alongside the Ford-O-Matic at the Fairfax Transmission Plant, and was put in midrange Ford and Mercury models. Because the original Ford-O-Matic started in second rather than first, it was marketed as a two-speed after the new three-speed transmissions were introduced. Production continued until it was replaced by the C4 in 1964 in smaller Ford and Mercury vehicles.