The Clay Foundation, established by brothers Buckner W. Clay and Lyell B. Clay in 1986, was a private, charitable foundation in Charleston. The brothers sold Clay Communications, a holding company which owned the Charleston Daily Mail, the Register-Herald (Beckley) and radio stations and newspapers in Virginia and North Carolina, to Thomson Newspapers in 1987. The Clay Foundation received $32 million from the sale. Charles M. Avampato, a former vice president of Clay Communications, became the President of the Clay Foundation and remained in that position until the foundation was dissolved in 2010.

The Clay Foundation philanthropy emphasized capital investments in buildings and community fund-raising campaigns. In 23 years of operation, the foundation provided $100 million in grants to 98 organizations. The Clay Center for the Arts & Sciences was the largest single grantee, receiving nearly $59 million dollars. Other major gifts were $5.2 to the University of Charleston for the Clay Tower, $5 million to the Kanawha County Public Library for a proposed new Charleston library, and $2 million to the University of Virginia School of Law to construct Buckner Clay Hall, named for the late father of the Clay brothers. The Clay Foundation contributed heavily to the United Way, the West Virginia Symphony Orchestra, and the Fund for the Arts.

In March 2010, the foundation had awarded all but $9 million dollars, which was to be distributed according to instructions left by Buckner and Lyell Clay. The foundation gave the building in which it was housed to the YWCA.

The Clay Foundation was separate from the Lyell B. and Patricia K. Clay Foundation of Charleston, Lyell B. Clay's private, charitable foundation that supported college and other music education programs throughout the state. The latter also closed in 2010.