Aleksanterinkatu

thumb|Aleksanterinkatu in 2024 Aleksanterinkatu (; "Alexander Street") is a street in Kluuvi, the commercial centre of Helsinki, Finland. In the city plan by Carl Ludvig Engel, it was the Decumanus Maximus, the main east–west street in the city, crossing the Cardo, Unioninkatu (Union Street) at the corner of the Senate Square.

thumb|Aleksanterinkatu in 2010 The street begins near the Presidential Palace and continues to meet with Mannerheimintie, the longest street in Helsinki. It runs past several famous buildings, such as Ritarihuone (the seat of Finnish nobility), the Helsinki Cathedral, the former headquarters of Suomen Yhdyspankki (later Finnish main office of Nordea), the main building of the University of Helsinki, and the Stockmann department store.