Princess Mathilde Sophie of Oettingen-Oettingen and Oettingen-Spielberg (in German: Mathilde Sophie, Prinzessin zu Oettingen-Oettingen und Oettingen-Spielberg; 9 February 1816 – 20 January 1886) was a member of the Princely House of Oettingen-Spielberg and a Princess of Oettingen-Oettingen and Oettingen-Spielberg by birth.

Through her marriage to Maximilian Karl, 6th Prince of Thurn and Taxis, Mathilde Sophie was also a member of the Princely House of Thurn and Taxis and Princess consort of Thurn and Taxis.

Mathilde Sophie was the eldest daughter and second-eldest child of Johannes Aloysius III, Prince of Oettingen-Oettingen and Oettingen-Spielberg (1788-1855) and his wife Princess Amalie Auguste von Wrede (1796-1871).

Mathilde Sophie married Maximilian Karl, 6th Prince of Thurn and Taxis, fourth child of Karl Alexander, 5th Prince of Thurn and Taxis and his wife Duchess Therese of Mecklenburg-Strelitz, on 24 January 1839 in Oettingen, Kingdom of Bavaria.

Mathilde Sophie and Maximilian Karl had twelve children: