Eugène Collache (29 January 1847 in Perpignan – 25 October 1883 in Paris) was a French Navy officer who fought in Japan for the shōgun during the Boshin War.

On 29 November 1868, Eugène Collache and Nicol left Yokohama on board a commercial ship, the Sophie-Hélène, chartered by a Swiss businessman.

Unable to achieve more than three knots due to engine trouble, the Takao trailed behind, and the Kaiten first joined battle.

The Kaiten approached the enemy ships and raised the Bakufu flag seconds before boarding the Imperial warship Kōtetsu.

Back in France, he was discharged from the armed forces and court-martialed as a deserter, but the sentence was light, and he was allowed to reenlist for the Franco-Prussian War together with his friend Nicol.