Maria Fyodorovna was the mother of Tsar Nicholas II, who was killed together with his family by the Bolsheviks in 1918.
Fyodorovna, a Danish-born princess before she married the future Tsar Aleksandr III in 1866, fled Russia after the 1917 Bolshevik revolution.
Her remains arrived in Russia from Denmark on September 26.
She was interred next to her husband in the Romanov vault in St. Petersburg's Peter and Paul Cathedral, where almost every tsar and tsarina since Peter the Great are buried.
(Reuters, dpa)