Princess Frederica or Princess Frederika may refer to:
- Princess Frederica Amalia of Denmark (1649–1704), duchess consort of Holstein-Gottorp, wife of Duke Christian Albrecht of Holstein-Gottorp
- Frederica Louisa of Hesse-Darmstadt (1751–1805), queen consort and second wife of King Frederick William II of Prussia
- Princess Frederica Charlotte of Prussia (1767–1820), daughter of King Frederick William II of Prussia and wife of Prince Frederick, Duke of York and Albany
- Frederica of Mecklenburg-Strelitz (1778–1841), wife of King Ernest Augustus I of Hanover
- Frederica of Baden (1781–1826), queen consort of King Gustav IV Adolf of Sweden
- Princess Frederica of Prussia (1796–1850), daughter of Prince Louis Charles of Prussia and wife of Leopold IV, Duke of Anhalt-Dessau
- Princess Frederica of Hanover (1848–1926), daughter of George V of Hanover and wife of Baron Alfons von Pawel-Rammingen
- Frederica of Hanover (1917–1981), queen consort of King Paul of Greece
Princess Friederike may refer to: