The station has a single platform from which trains depart to Ashford International and Eastbourne via Hastings.

The typical off-peak service at Three Oaks is one train per hour each way between Eastbourne (via Hastings) and Ashford International.

However, in the 2005 timetable change, trains on the line were extended to run to/from Brighton (via Eastbourne and Lewes) and operated as express services; as a result, service frequency at Three Oaks (as well as neighbouring Doleham and Winchelsea) was greatly reduced, to just 3 trains per day each way.

This led to the creation of a campaign the by Three Oaks and Winchelsea Action for Rail Transport (THWART) and the Marshlink Line Action Group (MLAG), which aimed to restore regular services from these stations.

[14] The May 2023 timetable change saw hourly services fully restored, with all trains now calling at both Three Oaks and Winchelsea seven days a week.