Lakeshore Entertainment, Hopscotch Features and Lionsgate announced the casting Friday.
Inspired by Mary Shelley's classic horror tale, the film was written and is to be directed by Stuart Beattie. It is based on a graphic novel by Kevin Grevioux, co-creator of the "Underworld" franchise.
Lionsgate is to distribute the film in the United States, Lakeshore will handle international sales and E1/Hopscotch will distribute it in Australia.
The movie is set for U.S. release Feb. 22, 2013.
"This story is all about what it means to be human, and there could be no more achingly human performance than the one Aaron gave in our own 'Rabbit Hole.' We are so excited to see what he will bring to this role," Lionsgate's co-Chief Operating Officer and Motion Picture Group President Joe Drake said in a statement. "This is a wonderfully imaginative script and we are looking forward to seeing it brought to life by a talented filmmaker, and to bringing this story to our loyal genre fans."
"We've tremendously enjoyed making our 'Underworld' franchise films and we are looking forward to working with Stuart and our partners at Hopscotch and Lionsgate to create a new world for a legendary character," added Lakeshore's Tom Rosenberg. "We know that Aaron, with his proven range, depth and intelligence, is going to make an iconic Adam."
Troy Lum of Hopscotch said: "We have wanted to work with Stuart on a big film in Australia and when we had the opportunity earlier this year to expand our relationship with Lakeshore on the creation of a potential franchise, it all came together."
"I, Frankenstein" is about the famous 19th century doctor's creature, Adam, who has survived to present-day due to a genetic quirk. Making his way to a dark, gothic metropolis, he finds himself caught in an all-out, centuries-old war between two immortal clans, the filmmakers said in a synopsis.
Eckhart's films include "Possession" and "The Dark Knight."