Jätkäsaari (Swedish: Busholmen) is a quarter in Helsinki, the capital city of Finland. It is part to the Kampinmalmi district and Länsisatama neighbourhood. It is was the location of the main container harbour in Helsinki until late 2008, when the harbour moved to the new facilities in Vuosaari. The terminal for passenger ferries to Tallinn, Estonia, remains in Länsisatama (literally West Harbour in Finnish).

What is now known as Jätkäsaari (literally Logger Island in Finnish), was originally a group of three islands: Jätkäsaari, Hietasaari, and Saukko. The sea between the islands and the continent was filled, creating a peninsula to house harbour facilities. The area became an island once more with the construction of the Ruoholahti Canal. With most of the harbour operations having moved to the new Vuosaari Harbour, the construction of a new residential and office area is expected to begin in late 2009, after a clean-up of contaminated soil is completed.

Pop singer-songwriter Madonna performed in the vacant harbour of Jätkäsaari as a part of her Sticky & Sweet Tour on August 6, 2009. The concert was attended by 85,000 people and, thus, the event was the biggest concert ever with an entrance fee in the Nordic countries. The surrounding air and maritime space were closed as a safety precaution during the evening and the night.