According to the 2001 census the parish had a population of 11,343. It gave its name to the wider borough when it was formed in 1974. The parish includes Knowsley Hall and Knowsley Park. There are three main built-up areas in the parish: the village of Knowsley, the nearby business park in the north west, and in the south-west a suburban area including Stockbridge Village and the northern fringe of Huyton.
The "ow" in the name can be pronounced as in "how" or as in "hoe", but Knowsley Village and the surrounding area usually use the latter.
The village of Knowsley (one of those in the Whiston RD) is hundreds of years older than the neighbouring city of Liverpool. Its name occurs in the Domesday Book (1086) as Chenulveslei and came from Anglo-Saxon Cēnwulfes lēah = "Cēnwulf's meadow".
There are a few notable entries in Knowsley's history: