Kolomna is an ancient city of Moscow Oblast, Russia, situated at the confluence of the Moskva and Oka Rivers, 114 kilometers (71 mi) (by rail) southeast of Moscow.

Mentioned for the first time in 1177, Kolomna was founded in 1140-1160 according to the latest archaeological surveys. Kolomna's name may originate from the Old Russian term for "on the bend (in the river)", especially as the old city is located on a sharp bend in the Moscow River. In 1301, Kolomna became the first town to be incorporated into the Moscow Principality.

Like some other ancient Russian cities, it has a kremlin, which is a citadel similar to the more famous one in Moscow and also built of red brick. The stone Kolomna Kremlin was built from 1525-1531 under the Russian Tsar Vasily III. The Kolomna citadel was a part of the Great Abatis Border and, although much of the surrounding wall was removed in the eighteenth century and materials used to construct other public buildings, the remaining stretch of wall, several towers, and some interior buildings have been preserved and held in a good shape. A museum is located inside. In front of the façade stands a statue of Dmitry Donskoy, celebrating the gathering of his troops in Kolomna prior to the Battle of Kulikovo in 1380.

The civic arms of Kolomna were granted by Empress Catherine II, who was influenced by the similar-sounding name of the famous Colonna family of Rome. Hence, the similar appearance of the arms, despite there being no connection between the Roman family and the city of Kolomna.

Due to sensitive military production of missile components, Kolomna was a closed city until 1994. It is not listed as a city of the Golden Ring, despite its kremlin and the large number of well-preserved churches and monasteries.