Joaquín Mariano Sucunza (February 15, 1946) is a prelate of the Roman Catholic Church. He serves as auxiliary bishop of Buenos Aires since 2000.
Born in Pamplona, Spain, Sucunza was ordained to the priesthood on November 27, 1971.
On Juli 22, 2000, he was appointed auxiliary bishop of Buenos Aires and titular bishop of Saetabis. Sucunza received his episcopal consecration on the following October 21 from Jorge Mario Bergoglio, archbishop of Buenos Aires, the later pope Francis, with auxiliary bishop of Buenos Aires, Mario José Serra, and emeritus auxiliary bishop of Buenos Aires, Guillermo Leaden, serving as co-consecrators.