Capt. John C. Ainsworth House

The John C. Ainsworth House is a historic building in Oregon City, Oregon, United States. It was built in 1851 for John C. Ainsworth, the main founder of the Oregon Steam Navigation Company. It is one of the oldest structures in the Portland area and remains in good condition. It is also the only two-story portico in Oregon. The house was added to the National Register of Historic Places in 1973.