SS Graf Waldersee was a transatlantic liner that was launched in Germany in 1898 and spent most of her career with Hamburg America Line (HAPAG). She was the third of a class of four HAPAG sister ships that were built in the United Kingdom and Germany between 1896 and 1899.
In 1919 HAPAG surrendered Graf Waldersee to the United States as part of Germany's World War I reparations to the Allies. She became the United States Navy troop ship USS Graf Waldersee (ID-4040) and was used to repatriate American Expeditionary Forces troops from Europe.
At the end of 1919 Graf Waldersee was transferred from the United States Shipping Board to the UK Shipping Controller. She was scrapped in Germany in 1922.
Postdampfer (German for mail steamer or postal steamship) is a historical term for a steam-powered ship contracted or operated to carry mail, goods, and passengers across regular maritime mail routes.