Perth Lade is a historic 4.5-mile (7.2 km)-long former mill lade in Perth and Kinross, Scotland. Created in the 11th century or earlier, it has been used to power several watermills, such as those that functioned at Perth's Lower City Mills, which have existed since the 18th century. Over its course, at least nineteen industrial sites existed; today, the remains of nine of these can be seen, the rest lost to inner-city development and housing schemes of the 20th and 21st centuries. A footpath follows the majority of the lade's course.