John Fraser (c. 1823 – June 4, 1878) was an American soldier and educator. He was the third president of the Pennsylvania State University, serving from 1866 until 1868, and the second Chancellor of the University of Kansas serving from 1867 to 1874. Fraser was born in Cromarty, Scotland, and studied at Aberdeen University. He graduated with a master's degree in mathematics. He emigrated to Bermuda to teach and then relocated to New York City to take charge of a private school. In 1851, he moved to western Pennsylvania and became professor of mathematics at Jefferson College.