The talented defender has accepted an offer to stay at Valley Parade, ending speculation that his days with the Bantams may be numbered.
The 25-year-old follows Ben Muirhead, John Swift and Craig Bentham who have all signed new deals over the last five weeks or so.
Bower scored his second goal of the season for City last Saturday, but it was not enough for Colin Todd's men who went down 2-1 to Hartlepool.