Engineering work is scheduled to close all rail lines between Oxford and Didcot Parkway from late on Saturday, October 31, until the early hours of Sunday, November 1, according to National Rail.
Several Great Western Railway services will be affected during the closure.
Late-night train journeys between Oxford and Didcot Parkway will be replaced by buses.
The 10.04pm Banbury-to-Didcot Parkway train will end its journey at Oxford.
A replacement bus is then due to leave Oxford at 10.45pm and serve every station on the route to Didcot Parkway.
The 10.45pm Didcot Parkway-to-Oxford service has been cancelled, with road transport providing an alternative.
Changes will also apply to passengers travelling to and from London Paddington.
The 10.50pm London Paddington-to-Oxford train will terminate at Didcot Parkway, where buses will continue to Oxford.
The 11pm Oxford-to-London Paddington service will originate from Didcot Parkway rather than Oxford.
Replacement transport will run from Oxford to connect passengers with the train.
Overnight disruption will remain in place on Sunday morning.
The 7.53am Oxford-to-London Paddington service will start from Didcot Parkway instead of Oxford, and passengers departing from Oxford have been advised to take a later train.
National Rail and Great Western Railway have asked passengers to allow additional time and check the latest travel information before setting out.
Replacement buses may have reduced capacity and could be busier than usual.