Dunbar attended Dayton's Central High School and graduated with honors in 1891. Paul, the only black in his class, became class president, became an editor of the The High School Times, and wrote the class song, a poem of eight stanzas which was sung at the commencement ceremonies on June 16, 1891, at the Grand Opera House.

In high school, Paul was popular among his fellow students and remained close friends with Orville Wright from the beginning of intermediate school throughout high school and into adulthood.