The name ‘Ormskirk’ is Old Norse in origin and is derived from Ormres kirkja, from a personal name, Ormr (which means "serpent" or dragon), and the Old Norse word for church.Ormr may have been a Viking who settled here, became a Christian and founded the church but there are no other records or archeological evidence to support this and Ormr's identity is unknown.
There is no reference to Ormskirk in the Domesday Book of 1086 but it has been suggested that it may have been part of Lathom at that time. In about 1189, the lord of Lathom granted the church of Ormskirk to Burscough Priory, which does suggest that Ormskirk had been subordinate to Lathom before that date.
The Parish Church of St Peter and St Paul is believed to be on the site of the original kirk, on a sandstone outcrop, and is the oldest building in the town. Its exact age is unknown; the building does contain some fragments of Norman architecture. The Parish Church has many connections with the Earls of Derby and the Stanley family. Many family members are buried in the church's Derby Chapel, including Thomas Stanley, the first Earl, who caused Richard III to lose his crown by changing sides at the Battle of Bosworth in 1485, and the Royalist James Stanley, the seventh Earl, who was beheaded at Bolton in 1651 after the Civil War. His body is buried in one coffin and his head in a separate casket.