Mannerheimintie (Swedish: Mannerheimvägen), named after the Finnish military leader and statesman Carl Gustaf Emil Mannerheim, is the main street of Helsinki, Finland. It was originally named Heikinkatu (Swedish: Henriksgatan), after Robert Henrik Rehbinder, but was renamed after the Winter War. The change of name was also suitable due to Mannerheim having paraded in along that road during the Finnish Civil War (1918), after German forces allied with Mannerheim's Finnish forces had retaken the city. That event is also portrayed in the landmark statue of Mannerheim sitting horseback. The statue is located along the Mannerheimintie just outside the modern arts museum Kiasma.
The street starts at Erottaja in the city centre, near the Swedish Theatre and continues in a northernly direction past the . It then continues as a main thoroughfare past the districts of Kamppi, Töölö, Meilahti, Laakso and Ruskeasuo, until it finally merges into a busy highway leading outside the city towards Hämeenlinna and Tampere. (Geographically, the highway only ends in central Tampere, having become a small street called Kalevan puistotie, meeting the major street Kekkosentie.)
Many famous buildings are located at or near Mannerheimintie. Besides the theatre and department store mentioned above, these include the House of Parliament, the main post office, the Kiasma modern art museum, the Finlandia Hall, the National Museum, the Helsinki Opera House, and Tilkka.