Harold J. Grimm (1901–1983) was an academic, historian, and writer and an expert on the Reformation.

Born in Saginaw in Michigan in 1901, Grimm gained his PhD at Ohio State University.

In 1978, Grimm received the Distinguished Teacher award at Ohio State University.

He contributed many articles to professional journals and was the American editor for the Archiv für Reformationsgeschichte.

[1] During his academic career Grimm collected about 200 volumes of books and pamphlets from the Reformation period.