The Jack Kerouac adaptation, co-starring Garrett Hedlund and Sam Riley, will now open in the UK on October 12. The drama was originally slated for release on September 21.
Film 4's Somerset House summer screen programme will host the UK premiere of Walter Salles's film on August 16.
On the Road was among the world premiere lineup at May's Cannes Film Festival.
"Obviously when everyone does a scene like that they say, 'Oh I felt so safe, Walter put me in an environment that was very informed by the natural story'. I loved pushing, I loved scaring myself," she said.
"To watch genuine experience on screen is just so much more interesting. I wanted to do it. The reason I want to do the job is because you read something and you're provoked on some level. It's just taking that further and being able to live it."
Stewart's final Twilight movie, Breaking Dawn - Part 2, will follow the release of On the Road on November 16.