Evidence for the existence of Kirkby dates back to the Domesday Book, and a reference to Cherchebi, with a population of 80. The town's main church, St. Chads', was established at the time, and a Norman watchtower still stands on one of the main roads.

Up until 1947, the area was largely farmland, with a few cottages and farm buildings, some of which survive to this day. During the Second World War, the area was the location of a Royal Ordinance Factory. In 1947, the Earls of Sefton, the owners of the land, sold the right to build to the Liverpool Corporation, who were seeking to develop the area around the city in an attempt to alleviate the housing shortage caused by the Blitz, and to provide housing for workers on the burgeoning industrial estate.

The current population of Kirkby stands at 36,400 [1], somewhat down from its peak in the 1960s of 60,000, largely due to falling birth rates and the slow decline of the industrial estate forcing workers to look elsewhere.

The M57 motorway runs along the eastern edge of Kirkby, and the town is well served by public transport, with train connections to Liverpool and Manchester (via Wigan). Construction on a new tram service linking Kirkby with Liverpool is expected to begin in late 2004 for completion by 2006.