The Take That star has penned 'Stronger Than I Am' for the 13-year-old's self-titled debut album, which will be released on October 24, reports The Sun.
It's the second track Barlow has worked on with a Simon Cowell act over the past few weeks.
X Factor winner Matt Cardle will release Barlow-written song 'Run For Your Life' as his first single proper on October 10.
Parke's debut record will contain 12 tracks and has been produced by Will Young collaborator Stephen Lipson.
The talent show star will release a cover of Vanessa Carlton's 'A Thousand Miles' as his first single, which features piano from fellow Britain's Got Talent finalist Paul Gbegbaje.
> Ronan Parke: 'Album will surprise fans'
Listen to Ronan Parke's 'A Thousand Miles' below: