27 January — Russia declared war on Japan; the battle of Chemulpo took place.
4 February — Japan severed diplomatic relations with Russia. The Japanese naval command received orders to begin military operations against the Russian fleet.
On the night of 9 February — a surprise attack by Japanese destroyers on the Pacific Squadron stationed in the outer roadstead of Port Arthur.
A battle took place in the Yellow Sea near the port of Chemulpo during the Russo-Japanese War of 1904–1905. The Russian cruiser "Varyag" and the gunboat "Koreets", in an unequal fight against a Japanese squadron, suffered heavy damage and were blown up and scuttled by their crews so they would not fall to the enemy.
Anton Chekhov wrote The Cherry Orchard.
2 July — Anton Chekhov died (aged 44).
28 July — Russia's Minister of the Interior, Plehve, was assassinated as a result of an attempt on his life.
In November — a Zemstvo Congress was held in Saint Petersburg, demanding the adoption of a republican constitution and civil liberties.
13 December — Nikolai Vasilyevich Sklifosovsky, a surgeon, died.