The 44-year-old, who held a similar position at Middlesbrough under Gareth Southgate, was at Valley Parade on Tuesday night to see the Bantams' 2-1 win over promotion contenders Rotherham.
Cooper's arrival allows David Wetherall, who had been assisting Jackson, to solely focus on his role as the club's youth-team coach.
Cooper played in over 600 games for Millwall, Nottingham Forest and Middlesbrough before retiring in 2006 and moving onto the reserve-team coaching staff at the Riverside Stadium.
Source: PA
Source: PA