Damien Marchesseault (or Marchesseau) (April 1, 1818 – January 20, 1868) was a Canadian-born American politician who served as the seventh mayor of Los Angeles from May 9, 1859, to May 9, 1860, and then again from January 7, 1861, to May 6, 1865. Marchesseault assumed the office one last time interrupting Cristobal Aguilar's first term in office for three months.

Born in St.-Antoine-sur-Richelieu, Quebec, Canada, Marchesseault was described as a carousing onetime New Orleans gambler. With Victor Beaudry, he started an ice vending company using ice from what is now known as Icehouse Canyon near Mount San Antonio.^{[citation needed]}

During his term as Zanjero of Los Angeles (water steward), Marchesseault and a partner laid wooden water pipes that burst and turned streets into sinkholes.

Struggling with mounting debts, he slipped into an empty Los Angeles City Hall Council chamber on Jan. 20, 1868, and shot himself to death.

Marcheassault Street in Los Angeles is named for him.^[1]

Marchesseault killed himself on 20 January 1868, leaving a suicide note to his wife, Mary Clark Marchesseault, stating his motivation was shame from his drinking and gambling debts.^[2]