Tununak is a Central Yup'ik Eskimo village located in a small bay on the northwest coast of Nelson Island, which lies on the Bering Sea coast in the Yukon-Kuskokwim Delta.

A federally-recognized tribe is located in the community, the Native Village of Tununak. The community was incorporated as a city in 1975, but it was dissolved in 1997 in favor of traditional council governance. The Alaska Department of Labor estimated Tununak population at 342 in 2011. It remains a traditional Yup'ik Eskimo village, with an active fishing and subsistence lifestyle. Seal meat, seal oil, and herring are the staples of the diet. Beluga whale and walrus are also hunted. Residents participate in a lottery to hunt musk-ox on Nelson or Nunivak Islands.

Tununak is the site of the first Catholic mission among the Central Yup'ik Eskimos. In 1889, missionary priests of the Society of Jesus opened a small chapel and school, built out of driftwood and sod. The parish was dedicated at first to Saint Alphonsus, then, a few years later, to St. Joseph.

After one year, there was recorded the baptisms of 43 adults and 128 children. However, after three years, because the island was so difficult to access, the school was closed and Tununak ceased to have a resident missionary for many years. Nevertheless, priests continued occasional visits from Akulurak. In 1927 another priest stayed on the island for a year. He put up a small cabin that served as both a residence and church for many years. Finally, another Jesuit priest took up station at Tununak and stayed from 1934 to 1962. His long-standing relationship and work with the Yup'ik people had a great influence.

Missionary efforts on Nelson Island proved most rewarding, when Native catechists began to participate in parish work, especially when the priests were traveling between villages. One such early catechist served St. Joseph in the 1930's and also oversaw the building of a new church. It was replaced in the 1960's, and updated in the 1980's. Native deacons also served at Saint Joseph since the 1980's. A Dominican Sister helped prepare catechists from 1978-87. Also during the 1970's a member of the Jesuit Volunteer Corps, operated a Montessori School at Tununak.

Parishes in the Yukon-Kuskokwim Delta are now served on a rotating schedule by ministry teams which may include priests, deacons, religious and trained lay staff members. Celebrations of the Word with Holy Communion may replace Sunday Mass when a priest is unavailable. St. Joseph Parish is served by visiting priests and ministers from the Diocesan Y-K Subregion D.