The Mercury Grand Marquis was a full-size rear-wheel drive luxury sedan that was sold by the Lincoln-Mercury division of the Ford Motor Company; the Grand Marquis was the flagship of the Mercury lineup. The nameplate had been in use since 1975 as the premium trim level of the Mercury Marquis; the Grand Marquis became a distinct model in 1983. The car was essentially Mercury's twin of the Ford Crown Victoria with which it shared the Panther platform along with the Lincoln Town Car.
With the discontinuation of the Mercury brand, the Grand Marquis ended retail production in October 2010 while production for fleet sales continued until January 2011. The last Grand Marquis, which was also the last Mercury ever produced, rolled off the assembly line on January 4, 2011. In continuous production for 36 years, the Grand Marquis was the longest-produced Mercury. In total, nearly 2.7 million were produced, making it the best-selling vehicle sold by the brand.