The clan name 'Ogasawara' derives from a place name in Koma County of Kai Province and it seems that the residence was located in presently Hokuto City, Yamanashi Prefecture (former Akeno-mura, Kitakoma County) where Ogasawara Maki and Yama Ogasawara no sho were and presently Minami Arupusu City, Yamanashi Prefecture (former Kushigata-machi, Nakakoma County) where Hara Ogasawara sho was.
小笠原氏の家名のもとになった「小笠原」の地名は甲斐国巨摩郡に見られ、小笠原牧や山小笠原庄があった現在の山梨県北杜市（旧北巨摩郡明野村）と、原小笠原庄があった現在の山梨県南アルプス市（旧中巨摩郡櫛形町）に居館があったとされる。