Waldo Hall is a building on the Oregon State University (OSU) campus in Corvallis, Oregon, United States.

The building's fourth floor, inaccessible to the public, is one of several reportedly haunted sites on campus.

[1][2][3] Waldo Hall was named in 1907 for Clara H. Waldo, the wife of pioneer and Oregon supreme court judge John B.

[4] She served on OSU's board of regents and was the first woman in the U.S. to serve on the board of a state college.

[4] She was also the first woman to address an OSU graduation class.