Australian team doctor Peter Brukner said in a statement released by Cricket Australia on Thursday afternoon that Hughes had died at St Vincent's Hospital.
"He never regained consciousness following his injury on Tuesday," he said.
"As a cricket community we mourn his loss and extend our deepest sympathies to Phillip's family and friends at this incredibly sad time....
Hughes, 25, was in an induced coma since the accident on Tuesday afternoon.
Hughes was hit on the side of the head when he attempted to hook the bouncer.
While he seemed to compose himself, the former Test opener leant forward, put his hands on his knees and, after a few seconds, suddenly collapsed head-first on to the pitch.
It was horrific, and the desperation of the moment was reflected by the way the umpires and his former teammates raced to his aid. http://www.smh.com.au/sport/cricket/phillip-hughes-dead-australian-cricketer-dies-after-bouncer-at-scg-20141127-11vcpt.html
I know next to nothing about cricket but after reading the coverage, this would be like Aaron Rodgers dying after being tackled on the football field.