The Ainsworth House, also known as the Capt. John C. Ainsworth House is a historic structure in Oregon City, Oregon. It was built for the main founder of the Oregon Steam Navigation Company, John C. Ainsworth, in 1851.

The Ainsworth House can be considered as a very unique building in its area, being the only 2 story portico in the state, as well as for being one of the oldest buildings in the Portland area that is still in excellent condition. The estate was also known as Mount Pleasant, and is designed by Absalom B. Hallock, one of Oregon?s earliest architects.

The Ainsworth House is currently a venue for weddings and corporate meetings, better known as the Ainsworth House and Gardens.