Oscar Waldemar Tietgens (26 March 1879 – 28 July 1917) was a German rower who competed in the 1900 Summer Olympics. He was part of the German boat Germania Ruder Club, Hamburg, which won the gold medal in the coxed fours final B.
He was killed in action during World War I while serving as a Leutnant der Reserve in the 49th Reserve Field Artillery Regiment. He is buried at the Hooglede German war cemetery in Hooglede, West Flanders, Belgium (grave 5305).
List of Olympians killed in World War I
Waldemar Tietgens at World Rowing
Waldemar Tietgens at Olympics.com
Waldemar Tietgens at Olympedia
Waldemar Tietgens at databaseOlympics.com (archived)