Otto von Rosen (11 May 1884 – 26 May 1963) was a Swedish military officer and sport shooter.
He was born in Stockholm, Sweden.
He participated at the 1908 Summer Olympics in London.
His best Olympic result was in the moving target small-bore rifle, where he placed 8th.During World War I he was suspected of espionage and sabotage in favour of Germany, after being arrested in Karasjok, Norway, in 1917.
In his confiscated luggage were found explosives, bottles with the toxin curare, and anthrax bacteria hidden in sugar.