Since departing his role with England 20 years ago, Cooley has worked with Cricket Australia and India’s national academy.
He will work above Neil Killeen, who was appointed England’s elite fast-bowling coach in 2023.
Although Cooley’s time will not wholly be dedicated to the England first team, it is another addition to a backroom staff McCullum had previously moved to slim down.
England went to the Ashes without a specialist fielding coach and missed 18 chances across the series.
Hopkinson left the set-up at the end of 2024, just as McCullum added England’s white-ball teams to his Test remit.
The 44-year-old former Sussex batter now returns for the T20 leg of the tour of Sri Lanka and the World Cup that follows.
“In white-ball cricket it makes an even bigger difference – you can win or lose a game from a dropped catch, or a catch,” said England white-ball captain Harry Brook.
“We felt like it was a good decision to bring in a fielding coach and try to make that area of our game a little more neat. It can win you a game.
“Hoppo’s a very good fielding coach and we’re looking forward to having him back.”
