The John M. Pfau Library is the library on the campus of California State University, San Bernardino in San Bernardino, California, United States.

It is named after the founding president of the university, Dr. John Martin Pfau.

[1] The first library director, Arthur E. Nelson, was appointed by Dr. Pfau in 1963.

Nelson began accumulating materials in a local warehouse and by 1965 had 50,000 books to move into Sierra Hall, one of the first (multipurpose) buildings on the campus.

In 1968, construction began on the current library building which was occupied in 1971.