The company began as the Kelley Kar Company founded by Les Kelley in 1918. Kelley started the company with three Model T Fords. His younger brother, Buster, worked with Kelley as a lot boy. By using data collected from the dealership, Kelley published the company’s first Blue Book in 1926, which became a standard guide in automotive trade in determining car value. Kelley Blue Book was formed in 1926, and the Kelley family continued its dealership business in Southern California for several decades. By the 1960s, the company moved from a car dealership to a specialty publisher and focused on the production of its automobile price guide.
In 1995, Kelley Blue Book created its company website, which contained tips and pricing information from its hardcopy guide.
In December 2010, Kelley Blue Book was purchased by AutoTrader.com. After its acquisition, the company operated as a subsidiary of AutoTrader.com, Inc.
In 2013, the company formed an alliance with Bitauto Holdings Ltd. to expand into China.
The company reports market value prices for new and used automobiles of all types, as well as motorcycles. For both new and used automobiles, KBB provides a Fair Market Range and Fair Purchase Price, based on actual transactions of what others are paying for a vehicle and adjusted regularly as market conditions change. For new automobiles, KBB also provides information about a car's MSRP and dealer invoice price. For used cars, KBB provides retail value, certified pre-owned value, trade-in value and private party value. Kelley Blue Book also offers expert and consumer vehicle reviews and ratings, and 5-Year Cost to Own information for new cars.
In 2012-2014, Harris Poll recognized Kelley Blue Book as the Online Auto Shopping Brand of the Year. In addition, the company received a WebAward in the automotive category of Outstanding Website for two consecutive years.