Mt. Rengyo, Mountain summit in Hinohara, Tokyo, Japan

Mt. Rengyo is a 1,016-meter summit on the border between Hinohara Village in Tokyo's Nishitama District and Midori Ward in Sagamihara, Kanagawa Prefecture. It lies in the southern Okutama mountains, east of Mt. Shoto, within Kanagawa Prefectural Jinba Sagamiko Natural Park. Trail signs also give the name as Rengyo-san.

The summit earned recognition as one of the Tama Hundred Mountains, a collection of peaks that reflects the natural heritage of the Okutama region. This designation highlights how important the mountain landscape is to the area's identity.

Trail signs on the approach give the peak as Rengyōsan as well as Rengyōhō, and the mountain is listed among the Tama Hundred Mountains of the Okutama range. The tea house associated with the area stands by the pass below, at Wada Pass, with the trail to neighbouring Mt. Jinba starting behind it.

The trailhead is reached from JR Fujino Station by taking a Kanachu bus bound for Wada and getting off at the Wada stop, a 14-minute ride. From there the climb to the summit takes about 2 hours 5 minutes and the descent about 1 hour 40 minutes. The peak lies on the border of Hinohara Village, Tokyo, and Midori Ward, Sagamihara, Kanagawa, within the Kanagawa Prefectural Jinba Sagamiko Natural Park.

The summit lies on the boundary between Hinohara Village in Tokyo and Midori Ward in Sagamihara, Kanagawa — only two prefectures, not three. The mountain is part of Kanagawa Prefectural Jinba Sagamiko Natural Park, and trail signs often give the name as Rengyō-san rather than Rengyō-hō.