Kovalainen competed in the 2004 Race of Champions at the Stade de France in Paris. In the first two rounds he defeated Formula One drivers David Coulthard and Jean Alesi, and then Ferrari Formula One star Michael Schumacher in a Ferrari 360 Modena in the semi-finals. He then beat World Rally Champion Sébastien Loeb in the finals using the Ferrari and a Peugeot 307 WRC car, although Kovalainen had never even sat in a rally car before, to become the first non-rally driver to win the Henri Toivonen Memorial Trophy and earn the title "Champion of Champions". He also participated in the Nations Cup alongside countryman Marcus Grönholm, but they finished in second place after Kovalainen's Ferrari 360 Modena broke down in the finals, losing to the French team of Loeb and Alesi.

He returned to the Race of Champions in 2005, defeating Bernd Schneider and Felipe Massa, but was then knocked out in the semi-finals by Tom Kristensen. Kovalainen won the Nations Cup with Grönholm in 2006, but was eliminated in the individual event at the semi-final stage by Mattias Ekström by a mere 0.0002 seconds. In 2007, Kovalainen and Grönholm again made the Nations Cup final, where they lost to the German team of Michael Schumacher and Sebastian Vettel. Kovalainen beat Vettel in the individual race, before crashing on the finish line in the next round against Andy Priaulx. He crossed the line out of control, and Priaulx pipped him.

Kovalainen returned to the event in 2010, where he withdrew after suffering a concussion in a crash after a heat race against Sébastien Loeb.