Getting to the Tokyo Disneyland is easy as it is well connected to central Tokyo via the Keiyo Line departing from Tokyo Station. From wherever you are in Tokyo, many lines converge at Tokyo station including the Shinkansen from other towns in Japan.
The Tokyo Disneyland is located at Maihama station on the Keiyo and Musashino Lines. These 2 lines share the track from Tokyo to Ichikawa-Shiohama before splitting off into their own lines. You may board any train departing except for any limited express service and the Commuter Rapid.
Remember to look out for your platform number as the island platform for Platforms 1 & 2 and Platforms 3 & 4 are separate.
The journey will take 16 minutes by local train and 13 minutes by Keiyo Rapid. Remember not to board the Commuter Rapid as it will skip Maihama station.
A Keiyo Line E233 EMU departing Maihama station.
You can also board Musashino Line trains, identified by the orange stripe. Only Musashino Line rapid trains run to and from Tokyo.
Once exiting Maihama Station, you may walk to Disneyland for around 5 minutes or board the monorail (not covered by Japan Rail Pass) to other destination such as the official hotels and Tokyo Disneysea.
The Disney Resort Line brings you around the Tokyo Disneyland area via a uni-directional loop starting from Resort Gateway station which connects with the Maihama JR station and Ikspiari shopping mall, and proceeds to Tokyo Disneyland, Bayside and Tokyo DisneySea stations. Tickets cost 260 yen for a single ride regardless of distance or 650 yen for a 1-day pass. More prices and options are available at the Disney Resort Line website.