Princess Olga Valerianovna Paley (2 December 1865 – 2 November 1929) was the morganatic second wife of Grand Duke Paul Alexandrovich of Russia.

She was born as Olga Karnovich in Saint Petersburg, the daughter of a Russian nobleman, Valerian Gavrilovich Karnovich (1833-1891), State councilor, Imperial Chamberlain and Vice-Director of the Department of General Affairs of the Ministry of State Property, and his wife, Olga Vasilyevna Meszaros (1830-1919), who was of Hungarian and German ancestry and whose family had been settled in Russia since the 17th century.

[1] In 1884, in Riga, Olga Karnovich wed General Erich Gerhard von Pistohlkors (1853–1935), a member of the Pistohlkors family, part of the Baltic German nobility, by whom she had four children, one son and three daughters: Olga began an affair with Grand Duke Paul Alexandrovich, causing a great society scandal.

The appalled Empress Maria Feodorovna of Russia recognized the imperial jewels and ordered her chamberlain to escort Olga out of the party.

Tsar Nicholas II was furious with Paul's disobedience, and he lamented that he "fear[ed] a whole colony of members of the Russian Imperial Family will be established in Paris with their semi-legitimate and illegitimate wives!

[7] She tried to turn Paul against his own son and wrote to her husband, "I have been telling you in every letter; 'don't trust Dmitri,' and I myself was deceived by his damned tricks!