Ancestors of Avalon is a 2004 historical fantasy novel by American writer Diana L. Paxson, based on an idea of Marion Zimmer Bradley.

Ancestors of Avalon is the missing link to the implied connection to the mythical Atlantis in Bradley's Avalon-series.

2500 years BC, Tiriki, Priestess of Light and of the Earth-goddess Ni-Terat, and her husband Micail, Priest of Light and Prince of the Atlantean state Atharrath, have to save themselves from the destruction of Atlantis and are forced to board different ships to the Isles of Tin (Britain).

Tiriki, and other Atlanteans who came with her, settle down in the swamplands surrounding the Holy Mountain (which is later going to be called the Isle of Avalon).

Micail and Tjalan, Prince of Alkonath, on the other hand, try to rebuild the lost glory of Atlantis and start building a huge stone circle – which will later be known as Stonehenge – in order to turn the people of Britain to slaves by using its tremendous powers.