William Holmes McGuffey (September 23, 1800 – May 4, 1873) was an American professor and college president who is best known for writing the McGuffey Readers, one of the nation's first and most widely used series of textbooks. It is estimated that at least 122 million copies of McGuffey Readers were sold between 1836 and 1960, placing its sales in a category with the Bible and Webster's Dictionary.