|Date of birth||Mecklenburg|
|Date of death||Sep 17, 1973 Munich|
Princess Oskar of Prussia, Countess von Ruppin (27 January 1888 – 17 September 1973) was the wife of Prince Oskar of Prussia.
She was born Countess Ina-Marie Helene Adele Elise von Bassewitz-Levetzow on 27 January 1888 at Bristow, Mecklenburg, Germany, to Count Karl Heinrich Ludwig von Bassewitz-Levetzow and his wife Countess Margarethe Cäcilie Luise Alexandrine Friederike Susette von der Schulenburg. Her brother was Werner Graf von Bassewitz-Levetzow.
On 31 July 1914 she married Prince Oskar of Prussia, son of Emperor Wilhelm II and his wife Augusta Viktoria of Schleswig-Holstein. Both the civil and religious ceremonies took place at Schloß Bellevue in Berlin, Prussia. Initially the union was considered morganatic, but on 3 November 1919 was decreed to be dynastic in accordance with the house laws of the royal house of Hohenzollern. Prior to her marriage, on 27 July 1914, Ina Marie had also gained the title Countess of Ruppin, and from 21 June 1920, was titled Princess of Prussia with the style Royal Highness. The couple had four children:
- Prince Oskar Wilhelm Karl Hans Kuno of Prussia (12 July 1915 Potsdam, Germany – 5 September 1939 Poland); died in World War II.
- Prince Burchard Friedrich Max Werner Georg of Prussia (8 January 1917 – 12 August 1988); married, but had no issue.
- Princess Herzeleide-Ina-Marie Sophie Charlotte Else of Prussia (25 December 1918 – 22 March 1989); married and had three children, including Prince Ernst-Johann Biron of Courland.
- Prince Wilhelm Karl Adalbert Erich Detloff of Prussia (20 January 1922 – 9 April 2007); married and had three children); was the last living grandchild of Emperor Wilhelm II; was the thirty-sixth Herrenmeister of the Order of Saint John (Bailiwick of Brandenburg).
- "Son Of The Kaiser To Wed A Countess. Prince Oscar to Contract a Morganatic Marriage with a Premier's Daughter". New York Times. May 27, 1914. Retrieved 2011-03-18.
Prince Oscar of Prussia, the fifth son of the Kaiser, is about to contract a morganatic marriage. His engagement to Countess Ina Marie von Bassewitz-Levetzow, daughter of the Premier of the Grand Duchy of Mecklenburg-Schwerin and former maid of honor of the Kaiserin, is officially announced today.
Princess Oskar of Prussia, Countess von Ruppin, died in Munich, Bavaria, on 17 September 1973.