Oaks Pioneer Church, formerly known as St. John's Episcopal Church, in southeast Portland in the U.S. state of Oregon is a non-denominational one-story chapel listed on the National Register of Historic Places. Built in 1851, it was added to the register in 1974. It is the oldest intact church building in Oregon. Located in Oaks Pioneer Park in the Sellwood neighborhood, the rectangular post-and-beam structure has a footprint of 18 by 42 feet (5.5 by 12.8 m). Fashioned from a partly completed house owned by pioneer Lot Whitcomb, it was the first Episcopal church in Oregon.