They also decided the tragedy was in no way caused by the supporters' behaviour.
Among those who were killed on April 15, 1989 were Ellesmere Port men James Delaney , 19, James Hennessy , 29, and Christopher Edwards , 29, along with Jonathon Owens , 18, of Chester, and Dodleston schoolboy Henry Rogers , 17.
A series of failures contributed to the tragedy, in which the fans were crushed in over-crowded pens at an FA Cup semi-final tie against Nottingham Forest in Sheffield.
These included the gross negligence of match commander David Duckenfield, the jury concluded.
Watch: The moment the families sing You'll Never Walk Alone outside court
The decision, which sparked cries of joy in the packed courtroom, could now pave the way for criminal action following the inquests.
Revealing their decision just after 11am, the jury said the 96 victims were unlawfully killed.
The courtroom heard there were major omissions in the 1989 operational order, and that police response to increasing crowds outside the ground was 'slow and uncoordinated'.
On the question of unlawful killing, they said it was a majority decision. Seven agreed with this question.
The decision brings an end to a 27 year battle for the truth waged by campaigners following the 1989 tragedy.
In reaching a decision over question six, widely seen as the most significant of the 14 asked of the nine person panel, the jury were told: “In order to answer ‘yes’ to that question [of unlawful killing], you would have to be sure that David Duckenfield, the match commander, was responsible for the manslaughter by gross negligence of those 96 people.
“When answering this question we are looking at Mr Duckenfield’s conduct and his responsibility.”
He said they would have to be sure that Mr Duckenfield owed a duty of care to the 96 people who died, that he breached that duty of care, that his breach caused their deaths and that the breach amounted to 'gross negligence'.
Since retiring to consider their decisions on Wednesday, April 6 the question over whether the 96 fans unlawfully died had appeared to be the one that had troubled the panel the most.
On Monday coroner Lord Justice Goldring told the jury he would accept a majority verdict over the question, meaning at least seven people needed to agree on the issue.
Today their decision was revealed to the joy of the campaigners who have fought for justice for 27 years.