The Cadillac CT6 (short for Cadillac Touring 6) is a full-size luxury car manufactured by Cadillac between 2016 and 2020 over two generations. The first generation CT6 was introduced at the 2015 New York International Auto Show and went on sale in the U.S. in March 2016. It is the first car to adopt the brand's revised naming strategy, as well as the first rear-wheel drive full-size Cadillac sedan since the Fleetwood was discontinued in 1996.

In 2020, the CT6 was discontinued in the United States, replaced by the existing electric Cadillac Celestiq liftback sedan.

The first-generation CT6 is built on a different platform than the smaller CTS and is engineered as a rear-wheel drive vehicle with optional all-wheel drive. In addition to its primary markets of North America and China, the CT6 was also offered in Europe, South Korea, Japan, and the Middle East.

General Motors discontinued the assembly of the Cadillac CT6 in the US in February 2020 due to poor sales and retooling of the Detroit/Hamtramck facility for electric vehicle production, beginning with the new GMC Hummer EV.

The CT6 is longer and wider than the XTS and offers more interior volume. It uses a mix of steel and aluminum, making it lighter than other cars in its size class. It was brought to market initially as an addition to, not a replacement for, the XTS, which has since been discontinued. Cadillac anticipated the CT6 would serve as a temporary flagship for the marque until a larger, more luxurious sedan would be marketed as the CT8. However, the CT8 did not come to fruition, and the CT6 remained the brand's flagship sedan.

For the American market, the CT6 was manufactured at GM's Detroit/Hamtramck Assembly plant. On March 11, 2016, the first CT6 delivery took place, having been delivered to the winner of a 2015 auction for the first CT6 sold. The vehicle sold for $200,000 at the auction. The car was "Platinum" trim level and painted Stellar Black Metallic.

The CT6 was offered in four trim levels: standard, Luxury, Premium Luxury, and Platinum. For the 2019 model year, the base (standard) trim was renamed Luxury, and a Sport trim was added, along with the CT6-V. There were nine exterior colors offered for the first year, and nine different interior packages, all featuring leather seats, with two reserved for the Platinum trim.

Standard CT6 features include the second generation CUE system, 4G LTE connectivity, and a Bose audio system: base models were equipped with an 8-speaker Bose system, which was upgraded to a Bose Centerpoint 10 speaker system included with the "Luxury" and "Premium Luxury" package, or a 34-speaker Bose Panaray audio system included with the top level "Platinum" package. Cadillac once again offers the Enhanced Night Vision which previously had been discontinued in 2004 with the DeVille. Available equipment includes Adaptive Cruise Control, as well as Magnetic Ride Control coupled with accident avoidance technologies. New with the CT6 is the Rear Camera Mirror, which uses streaming video from a camera that displays within the rear view mirror, which provides an enhanced view without obstructions from the "C-pillar" and passengers sitting in the rear area. The front seats can be adjusted 14 different ways, with an optional 16- or 20-way adjustment package that includes heated and cooled seat with a massage feature for both front and rear passengers. Another option package provides rear seat passengers with retractable 10" LCD screens that rise out from the back of the front seat seatbacks, behind the front seat headrests; these monitors can play Blu-ray content from user-supplied portable devices, and were introduced on the Cadillac Escala concept car.