Kadriorg (Estonian for "Catherine's Valley") is a subdistrict (Estonian: asum) in the district of Kesklinn (Midtown), Tallinn, the capital of Estonia. It has a population of 4,561 (As of 1 January 2015). The subdistrict name derives from the Catherinethal, a Baroque palace of Catherine I of Russia. It is one of the wealthiest regions in Estonia.
Kadriorg is known for the Kadriorg palace and the surrounding park, commissioned by the Russian Czar Peter the Great. Nowadays the park is a location of several museums including the Kadriorg art Museum (in Kadriorg palace), KUMU, Mikkel, Peter the Great and Eduard Vilde museums. Nearby is the Russalka Memorial which commemorates the loss of a Russian warship in 1893.
The official Presidential Palace of the President of Estonia is situated next to Kadriorg Palace in the park.