The appointment is scheduled to be announced later today and takes effect August 1, said GM spokesman Terry Rhadigan.
Mr Nesbitt, known for penning Chrysler's PT Cruiser, has spent eight years at GM, where he is currently in charge of North American design.
His move to Cadillac is in line with a strategy outlined by Vice Chairman Bob Lutz on July 10, when he postponed his retirement to take a new role as chief of marketing and communications with oversight of design.
Mr Lutz, 77, said then that he would put design at the centre of GM's advertising message, and Mr Nesbitt will report to Mr Lutz.
Mr Rhadigan said interim Cadillac general managers Steve Hill and Steve Shannon will be reassigned and their new positions will be announced soon.
Mr Nesbitt has been GM's vice president of North American design since June 2007, and before that was executive director of design for GM Europe.
He came to GM in 2001 from Chrysler, where he worked with Mr Lutz and designed the PT Cruiser. He later crafted GM's version of the retro wagon, Chevrolet's HHR.