Treadwell Mansion and Carriage House, is a historic mansion with carriage house built in c. 1875 in the Rockridge neighborhood of Oakland, California, U.S..[1][2] The two buildings used to be part of the campus for California College of the Arts, from 1922 until 2022.

[3] The Treadwell Mansion and Carriage House has been listed on the National Register of Historic Places since July 15, 1977;[4] listed as a California Historical Landmark since July 15, 1977;[5] and listed as an Oakland Designated Landmark under the name "Treadwell Hall" since August 5, 1975.

[1] The building was designed by architect Clinton Day, in the Gothic Revival and Eastlake-Stick style.

[1] In 1922, it was purchased by Frederick Heinrich Wilhelm Meyer, the founder of the California School of Arts and Crafts (now California College of the Arts).

[1] In 2022, the art school left the building and moved to San Francisco.