No, the Japan Rail (JR) Pass is not valid on the Hakone Tozan Railway. The JR Pass only covers transportation on the JR national network, whereas the Hakone Tozan Railway is a private line owned by the Odakyu Group. To travel on this scenic mountain railway, which runs from Odawara to Hakone-Yumoto and up to Gora, you must either purchase individual tickets or use the Hakone Free Pass. The Hakone Free Pass is widely considered the best value for 2026 travelers, as it covers all major transport in the Hakone area, including the railway, the cable car, the ropeway, the sightseeing cruise on Lake Ashi, and several local bus lines. While you can use your JR Pass to take the Shinkansen or local JR trains as far as Odawara Station, you will need to switch to the Odakyu/Hakone Tozan system from there. If you have a digital IC card like Suica or Pasmo, you can also use that to pay for individual rides on the Tozan line.