The Citroën C4 WRC is a World Rally Car built for the Citroën World Rally Team by Citroën Racing to compete in the World Rally Championship. It is based upon the Citroën C4 road car and replaced the Citroën Xsara WRC. The car was introduced for the 2007 World Rally Championship season and has taken the drivers' title each year since in the hands of Sébastien Loeb, as well as the manufacturers' title in 2008, 2009 and 2010.
The C4 WRC and Loeb maintained a 100% record on asphalt events during its WRC career, winning all 13 pure asphalt rounds of the World Rally Championship.
The car made its debut at the 2007 Monte Carlo Rally in the hands of Citroën World Rally Team drivers Sébastien Loeb and Daniel Sordo. Loeb won the rally after leading throughout, with Sordo finishing as runner-up, with the pair winning the first nine of 15 stages. Loeb went on to win seven of the remaining 15 rallies that season to beat Ford's Marcus Grönholm to the title by nine points. Sordo finished fourth in the standings.
Citroën retained Loeb and Sordo in their team for 2008, with Loeb winning 11 out of 15 rallies to take the title, while Sordo finished third in the standings. This was enough for Citroën to regain the manufacturers' crown.
C4 WRCs were also run by privateer squad PH-Sport for Conrad Rautenbach and Urmo Aava during the season, as well as for Junior World Rally Championship winner Sébastien Ogier at the final event of the season, Rally GB. Ogier lead the event early on despite it being his first in a WRC car.