Robert Dermot O'Flanagan (March 9, 1901—December 31, 1972) was an Irish-born prelate of the Roman Catholic Church who served as bishop of the Diocese of Juneau from 1951 to 1968.
Robert O'Flanagan was born in Lahinch, County Clare, and attended the Dominican School in Dún Laoghaire and Belvedere College in Dublin. He continued his studies at Ignatius College in Valkenburg in the Netherlands, where he was ordained to the priesthood on August 27, 1929. Returning to Ireland, he taught at Clongowes Wood College in County Kildare from 1930 to 1932. He then volunteered to do missionary work in Alaska, arriving at Juneau in 1933. He served in Seward before serving as pastor of Holy Family Church in Anchorage (1933-1951).
On July 9, 1951, O'Flanagan was appointed the first Bishop of the newly erected Diocese of Juneau by Pope Pius XII. He received his episcopal consecration on the following October 3 from Bishop Francis Doyle Gleeson, S.J., with Bishops Charles Daniel White and Joseph Patrick Dougherty serving as co-consecrators. He attended all four sessions of the Second Vatican Council between 1962 and 1965. After seventeen years as bishop, he resigned on June 19, 1968; becoming a titular bishop. He later resigned his titular see on January 13, 1971. He died at age 71.