Mårten Trotzigs gränd, alley in Gamla stan, Stockholm, Sweden

Mårten Trotzigs gränd is a pedestrian alley in Gamla stan, Stockholm, running from Västerlånggatan and Järntorget up to Prästgatan and Tyska Stallplan. Its 37 steps taper to a width of 90 centimetres at the narrowest point, making it Stockholm's narrowest street. The alley is flanked by the facades of older buildings.

The alley was recorded in 1544 as Tronge trappe grenden, the narrow stairs alley, and in 1608 as Trappegrenden. The merchant Mårten Trotzig, born in Wittenberg and a burgher of Stockholm from 1581, bought properties here in 1597, 1599 and 1600. Petrus Tillaeus's 1733 map names it Trotz gränd; it was closed at both ends in the mid-19th century, reopened in 1945, and the name was officially confirmed in 1949.

The passage is named after a 17th-century merchant whose legacy remains tied to this part of the city. The tight corridor and surrounding buildings show how people organized their lives and commerce in a dense urban space.

The passage is open and freely accessible year-round, though it can be slippery in wet conditions. The narrow width requires visitors to walk single-file, and it tends to be less crowded during off-peak hours.

The alley's name was not fixed until 1949, though a 1733 map by Petrus Tillaeus already labelled it Trotz gränd. In the late 18th century an attempt was made to rename it Kungsgränden, and from the mid-19th century until 1945 it was closed off by planks at both ends.