Louis Marcellus Nagelsen (born Louis Marcellus Nagelsisen) (June 29, 1887 – October 21, 1965) was a Major League Baseball catcher who played for one season. He played for the Cleveland Naps for two games during the 1912 Cleveland Naps season. He attended the University of Notre Dame.
Lou Nagelsen
| Given name: | Louis Marcellus Nagelsen |
| Nicknames: | None |
| Primary Pos: | Catcher |
| Hght/Wght: | 6'2" / 180 lbs |
| Bats/Throws: | R / R |
| Born: | Jun 29, 1887 in Piqua, OH |
| Died: | Oct 22, 1965 in Fort Wayne, IN (78 years old) |
| Debut: | Sep 10, 1912 |