Caprica, which is set half a century before the channel's signature series, will be produced by Battlestar's Ronald D. Moore and David Eick.
According to Variety, the programme will star Eric Stoltz, Paula Malcomson, Esai Morales and Polly Walker.
Sci Fi Channel president Dave Howe said: "We want people to come to this who have never heard of Battlestar Galactica.
"I think, because [Galactica's] backdrop was space and spaceships, there was a barrier to entry for some viewers. Caprica has none of that.
"It's an intense family drama set on an Earthlike planet in the near future, speaking to a lot of the ethical dilemmas that we as a human race are going to have to face very shortly."
Production is scheduled to begin next year, with the series expected to air early in 2010.