Leissegues joined the Navy in 1778, at age 20. He served on the frigate Oiseau and took part in patrol in the English Channel, before being transferred on the Nymphe. In 1780, he was promoted to lieutenant de frégate and joined the Magicienne. In 1781, Leissegues served under Suffren and took part in the campaigns of the Franco-Indian alliances. He received a wound at the head during the Battle of Providien. Leissègues returned to Toulon in August 1814. He served under the Bourbon Restoration, rising to vice-admiral, until 1818.