The Glaze Brook, or River Glaze, is a minor river in the River Mersey catchment area, England. From Hope Carr (just inside Leigh) to the River Mersey it forms the county boundary with Cheshire. It is about long and its main tributaries are the Astley, Bedford, Hey, Pennington, Shaw and Westleigh Brooks.
Pennington Brook starts at the outflow of Pennington Flash close to Aspull Common. Pennington Flash is fed by Hey Brook, a continuation of Borsdane Brook, which runs southwards from Blackrod.
Glaze Brook originates at the confluence of Pennington Brook and Moss Brook, approximately 120 m north of Hawkhurst Bridge. After picking up the waters of Bedford Brook, which runs southward from Leigh and the Black or Moss Brook coming west from Worsley via Chat Moss, the brook turns southward, ultimately draining into the River Mersey section of the Manchester Ship Canal near Cadishead.
The Glaze Brook's catchment drains the flat lowland around Leigh which reaches a maximum altitude of 158 mAOD. The brook flows through largely agricultural land. Its tributaries extend into former mining and industrial areas in which mining subsidence has created flashes (lakes) at Pennington and Westleigh. The underlying geology is the sandstone and coal measures of the Lancashire Coalfield.