Västerlånggatan (Swedish: The Western Long Street) is a street in Gamla stan, the old town of Stockholm, Sweden. Stretching southward between the squares Mynttorget and Järntorget, it follows the course of the city's now demolished 13th century defensive wall.
The blocks along the street are elongated but only a few metres in width; those on the eastern side oriented lengthwise, and those on the western crosswise. Only four blocks thus forms the eastern side of the street while some 20 are lined-up along the western side. Most of the front doors of the buildings are located either on the quite Prästgatan, the parallel street passing along the eastern side, or in one of the numerous alleys on the street's western side. The intact façades of the northernmost blocks are hiding the semi-detached offices of the Parliament. To the south of those are the remaining numerous and very narrow blocks and alleys which before the great fire of 1625 occupied the entire western side of the street.