Katajanokka

thumb|right|Uspenski Cathedral Katajanokka (; ) is a neighbourhood of Helsinki, Finland, with around 5,000 inhabitants in 2023. The district is located adjacent to the immediate downtown area, though in the first major town plan for Helsinki from the mid-18th century, the area fell outside the fortifications planned to encircle the city.

Originally, Katajanokka was a headland of the Helsinki peninsula but is now technically an island, as a small canal was dug across the base of the headland in the 19th century. There are four bridges across the canal connecting Katajanokka with the Helsinki Market Square and Aleksanterinkatu area in mainland Helsinki.