Louis was born in Doncaster, South Yorkshire, England to Troy and
Johanna. His parents split up when Louis was young. When his mother remarried, Louis took on his stepdad Mark Tomlinson's name. He has four younger half-sisters by his mom; Charlotte, Félicité, and twins Daisy and Phoebe. He has one younger half-sister by his father, Georgia. Mark and Jay divorced in 2011.
Louis auditioned for The X Factor with "Hey There Delilah" by Plain White T's. He received three votes out of the three judges present, and was sent to Bootcamp. At Bootcamp, he sang Bob Dylan's "Make You Feel My Love" before being rejected, and put into One Direction.