 In Geisenheim on 22 May 1947, Stülpnagel married the Geisenheim native Lucia Luise Gräfin von Ingelheim gen. Echterin von und zu Mespelbrunn (25 December 1917 – 3 June 1958).Lucia Luise was the daughter of Philipp Rudolf Graf von Ingelheim, Archchamberlain of the Duchy of Nassau, and Leopoldine Schenk Gräfin von Stauffenberg.Stülpnagel competed for Nazi Germany in the 1936 Summer Olympics held in Berlin in the 4x400 metre relay where he won the bronze medal with his team mates Helmut Hamann, Harry Voigt and Rudolf Harbig.