Kirkby Brook is a minor river located entirely within the town of Kirkby, situated in the Metropolitan Borough of Knowsley in Merseyside, England. Locally, the watercourse is the name given to Simonswood Brook as it passes through the area, functioning as a tributary to the River Alt within the larger Alt catchment.\n\nThe brook's path begins near St Chad's Church, where it flows southward toward Littlebrook Lane. At this point, the river turns in a southwestern direction before eventually merging into the River Alt near Lime Tree Woods. In 2016, the environmental status of the brook was monitored by the Environment Agency, a non-departmental public body sponsored by the United Kingdom's Department for Environment, Food and Rural Affairs, which classified the abundance and diversity of its invertebrate life as 'poor'.
