The River Medlock is a river located in Greater Manchester, England. It flows through the city and is a tributary of the River Irwell. The river is approximately 10 miles long and has its source near Ashton-under-Lyne, eventually joining the Irwell near Manchester city center. Historically, the River Medlock played a significant role in the industrial development of the region. It was used for transporting goods and powering mills during the Industrial Revolution. Today, the river is part of various environmental and recreational initiatives aimed at improving water quality and enhancing the surrounding green spaces.