| Peter | |
|---|---|
| Duke of Oldenburg | |
 | |
| Born | 26 August [O.S. 14 August] 1812 Yaroslavl, Yaroslavl Governorate, Russian Empire |
| Died | 14 May [O.S. 2 May] 1881 (aged 68) Saint Petersburg, Russian Empire |
| Burial | |
| Spouse | |
| Issue | Grand Duchess Alexandra Petrovna of Russia Duke Nicholas Duchess Cecile Duke Alexander Duchess Catherine Duke George Duke Constantine Therese, Princess Therese Petrovna Romanovskaya |
| House | Holstein-Gottorp |
| Father | Duke George of Oldenburg |
| Mother | Grand Duchess Catherine Pavlovna of Russia |
| Religion | Lutheranism |
Duke Constantine Frederick Peter of Oldenburg (‹See Tfd›German: Konstantin Friedrich Peter; ‹See Tfd›Russian: Пётр Гео́ргиевич Ольденбу́ргский, romanized: Pëtr Geórgievič Ol'denbúrgskij; 26 August [O.S. 14 August] 1812 – 14 May [O.S. 2 May] 1881) was a Duke of the House of Oldenburg. He was the grandfather of Duke Peter of Oldenburg as well as grandfather of Grand Duke Nicholas Nikolaevich, General of the Imperial Russian Army during World War I. His great-great-grandson, Nicholas Romanov, was the President of the Romanov Family Association until his death in 2014.
Peter of Oldenburg was a scholar and philanthropist. He was also noted composer of music. In 1857 he composed the music for Marius Petipa's ballet La Rose, la Violette et le Papillon. The Pas d'Esclave from the ballet Le Corsaire, which is taken from his score for this work, is still heard in theatres all over the world.