This is due to engineering work taking place between Crawley and Horsham closing all lines.
An amended service will also run between Southampton / Portsmouth / Littlehampton and London Victoria, Southern said.
Customers are advised to plan their journey using the National Rail Enquiries Journey Planner.
Meanwhile, the A272 at Cowfold remains closed for emergency repairs between Picts Lane and Wineham Lane – after a lorry overturned on Thursday night – spilling tar onto the road.
The road closure is affecting traffic between Cowfold and Bolney.