Dia Art Foundation has named art historian and curator James Meyer to fill two leadership posts as the New York-based nonprofit known for its cavernous exhibition space in Beacon, N.Y., works to reassert its presence in Chelsea.

In January Mr. Meyer, now an associate curator of modern art at the National Gallery of Art in Washington, D.C., will become Dia’s deputy director. He will also be chief curator, a newly created role that Dia’s director, Jessica Morgan, said reflected the foundation’s expanded scope.