Aleksanterinkatu is a historic central street in Helsinki, also known as Alexander Street. It was named in honor of Russian Emperor Alexander I and is one of the few streets that has retained its name since the time when Finland was part of Russia. Most similar streets have been renamed.

According to the urban planning of Helsinki developed by architect Carl Ludwig Engel, this street was intended to be the main latitudinal artery of the city, which at that time was significantly smaller in size. The street begins near the Presidential Palace, which previously served as the residence of Russian governors-general of Finland, passes through Senate Square, and continues to the modern Mannerheim Avenue, which is the main and longest street in Helsinki.

Originally, the street was called Suurikatu, which translates to 'Big Street,' but in 1833 it received its modern name. In conversation and writing, it is often referred to as Aleksi.

Throughout its history, Aleksanterinkatu has been and remains one of the main shopping streets in Helsinki. It is home to numerous stores from various retail chains, including one of the first major stores in Finland, 'Aleksi, 13,' the first flagship store of 'Nokia,' as well as banks, restaurants, and cafes. Additionally, the street is one of the main tourist attractions in the capital of Finland. Since 1948, it has been traditionally decorated during the Christmas holidays.