Auto Trader Group plc is a British automotive classified advertising business. It specialises in new and second-hand automotive sales, including cars sold by private sellers and trade dealers.

Auto Trader was founded in 1975 by John Madejski. Madejski brought this idea back from the United States and set up the business with Paul Gibbons in 1977. The first Auto Trader to be established was Hurst’s Thames Valley Trader in 1977.

This was followed by the publication of a second title, Southern Auto Trader, which launched in 1981; the business was then known as Hurst Publishing.

European venture capitalists BC Partners bought a stake in the business from John Madejski in July 1998 for £260m; then Guardian Media Group, which had acquired Automart in 1982, merged that business with Hurst Publishing in May 2000 so creating Trader Media.

In April 2011, the business became the focus of an online petition by a group called the Motor Traders Advertising Union, proposing a mass pullout by motor dealers in the country frustrated by increases in advertising charges. In October 2013, AutoTrader.co.za (Auto Trader South Africa) a subsidiary of the Auto Trader Group, was sold off to become an independent South African company.

In January 2014, Apax Partners bought the business from Guardian Media Group for £600m. In March 2014, the company rebranded and became known as Auto Trader, and in March 2015, Auto Trader Group launched an initial public offering, with a market capitalisation of about £2bn.