Tora Magnusdatter (Þóra Magnúsdóttir) (born c. 1100) was a daughter of King Magnus III of Norway (Magnus 3 Olavsson Berrføtt).
Tora married an Icelandic man and moved to Iceland. Her husband, Loftur Sæmundsson was a chieftain of Oddi at Rangárvellir in the south part of Iceland. He was a member of the Oddaverjar clan and son of Icelandic priest and scholar Sæmundur fróði Sigfússon. Their son Jón Loftsson was later chieftain at Oddi.
Descendants of Loftur and Tora included Þuríður Sturludóttir (born c. 1228), who married Hrafn Oddsson (born c. 1225), a descendant of Sakallagrímur Kveldúlfsson (Skalla-Grímr), the father of skald Egill Skallagrímsson. With the birth of Jón korpur Hrafnsson, the feuding clans of the Fairhair and Skalla-Grímr dynasties were united.