Meunier served in the division of Pierre Dupont de l'Étang in the 1805–1807 campaigns. On 11 October 1805, the 9th Light Infantry fought at the Battle of Haslach-Jungingen as part of Dupont's 1st Division of Marshal Michel Ney's VI Corps. During this remarkable action, Dupont's 5,350 infantry, 2,169 cavalry and 18 guns held off 25,000 Austrians under Karl Mack von Leiberich. The division was involved in a mopping-up action at Herbrechtingen on 17 October. Dupont's division fought at the Battle of Dürenstein on 11 November. The 9th Light Infantry captured two colors from the Russian Viatka Musketeer Regiment during the action. Meunier became a commander of the Légion d'honneur on 25 December 1805.