St. Jacob's Church is a historic Russian Orthodox church in Napaskiak, Alaska, United States. It was listed on the National Register of Historic Places in 1980. It has a 62 by 23 feet (18.9 m × 7.0 m) plan, extended out from an original 32 feet (9.8 m) building length, from when it was built sometime in the early 1900s. The western 26 feet (7.9 m) part of the building was added in two stages over the course of the 20th century, and was done to closely match the properties of the existing structure. The second addition added a vestibule area and a small bell tower topped by an Orthodox onion dome. The building is clad in novelty siding.