| Olga Constantinovna of Russia | |
|---|---|
 | |
| Queen consort of the Hellenes | |
| Tenure | 27 October 1867 – 18 March 1913 |
| Regent of Greece | |
| Regency | 17 November 1920 – 19 December 1920 |
| Born | 3 September 1851 Pavlovsk Palace, Pavlovsk, Saint Petersburg, Russian Empire |
| Died | 18 June 1926 (aged 74) Rome, Italy, or Pau, France |
| Burial | 17 November 1936 Royal Cemetery, Tatoi Palace, Greece |
| Spouse | |
| Issue | |
| House | Holstein-Gottorp-Romanov |
| Father | Grand Duke Constantine Nikolaevich of Russia |
| Mother | Princess Alexandra of Saxe-Altenburg |
| Signature |  |
Olga Constantinovna of Russia (Greek: Όλγα; 3 September [O.S. 22 August] 1851 – 18 June 1926) was Queen of Greece as the wife of King George I. She was briefly the regent of Greece in 1920.
A member of the Romanov dynasty, Olga was the oldest daughter of Grand Duke Constantine Nikolaievich and his wife, Princess Alexandra of Saxe-Altenburg. She spent her childhood in Saint Petersburg, Poland, and the Crimea, and married George in 1867 at the age of sixteen. At first, she felt ill at ease in the Kingdom of Greece, but she quickly became involved in social and charitable work. She founded hospitals and schools, but her attempt to promote a new, more accessible, Greek translation of the Gospels sparked riots by religious conservatives.
On the assassination of her husband in 1913, Olga returned to Russia. When the First World War broke out, she set up a military hospital in Pavlovsk Palace, which belonged to her brother. She was trapped in the palace after the Russian Revolution of 1917, until the Danish embassy intervened, allowing her to escape to Switzerland. Olga could not return to Greece as her eldest son, King Constantine I of Greece, had been deposed.
In October 1920, Olga returned to Athens on the fatal illness of her grandson King Alexander of Greece. After his death, she was appointed regent (in November) until the restoration of Constantine I the following month. After the defeat of the Greeks in the Greco-Turkish War of 1919–22 the Greek royal family were again exiled and Olga spent the last years of her life in the United Kingdom, France and Italy.