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 five younger sisters; Charlotte, Félicité, and twins Daisy and Phoebe. Mark and Jay divorced in 2011.
He was a sixth form student at Hall Cross School, a state comprehensive school and previously a pupil at The Hayfield School. While he was a student at Hall Cross, Louis starred in several musical productions.
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.
Following The X Factor, One Direction signed a record contract with Sony Music subsidiary Syco Music. They released their studio album,Up All Night.
Louis dated his high school girlfriend, Hannah Walker, throughout his time on The X Factor.
After their split, he began dating Manchester University student, Eleanor Calder, in late 2011. They celebrated their one year anniversary on November 17, 2012.