A loyalist white line picket over the flag issue took place in the town on Friday evening, passing off peacefully.
But, a short time later, a crowd of up to 100 people gathered in the Carnmoney Road area.
Trouble broke out at around 8.30pm when rioters attacked police with bricks and bottles and a car was set on fire.
None of the injured officers required hospital treatment.
It is understood the disorder erupted after a group of loyalists attempted to remove Irish tricolour flags from lampposts and were challenged by the PSNI.
A building where the constituency office of Justice Minister David Ford is located was also attacked. A business on the first floor was badly damaged and windows were smashed.
A bus was also hijacked in the Carnmoney Road area after being surrounded by a crowd.
Two masked men told the bus driver to park his vehicle across the road, which he did.
A PSNI spokesperson said: "However, police were quickly on the scene and the crowd was dispersed and the bus driver drove his vehicle off. There was slight damage caused to the vehicle."
It is not thought anyone was injured.
Police said calm was restored to the area on Friday night and the road later reopened.
An ongoing investigation into the disorder is underway, a police statement added.
"The vast majority of people in Glengormley are adding real value to their local community, however, a very small minority are intent on causing disruption and harm.
"We need the continuing assistance and co-operation of local community groups and residents as we carry out our investigations," the statement read.
These riots are disgraceful and serve no purpose except to cause disruption.
Secretary of State Theresa Villiers
NI Secretary of State Theresa Villiers said: "The actions of those involved were shocking.
"It is totally unacceptable that policemen were injured as they went about their duty protecting the whole community," she continued.
"These protests must come off the streets and allow NI's political leaders to work together towards a resolution."
Community representatives, who spoke to UTV, believe the violence was orchestrated by people who live outside the area.
UUP Councillor Mark Cosgrove said that "a more sinister element" was involved in the violence which broke out shortly after the peaceful flags protest.
"What happened last night is not representative of this community that I am very proud to represent and it is not representative of the people in it," he said.
"And it certainly isn't representative of the pro-union people in it, who want nothing to do with people who are going to damage property, wreck commercial premises and try and drag us back to a place we don't want to go and we are not going."
Alliance Councillor John Blair has condemned the "despicable" attack on the office of his party leader during the violence.
There is no place for this unacceptable behaviour in our society.
Alliance Councillor John Blair
Mr Blair said it was important that town centres remained shared spaces open to the whole community.
"The most disappointing aspect is that a lot of people are working in the area on behalf of all the community to make Glengormley a safe and successful place.
"Community, business and Council representatives alike have taken great strides towards creating a shared community, especially bringing young people from all backgrounds together," he added.
"No doubt the people who caused what looked like a planned outbreak of violence had a clear intent to disrupt community relations.
"During the disturbances the building in which David Ford's constituency office is based was also attacked, with damage done to the office of another tenant. This was a despicable attack and I would urge anyone with information to contact the PSNI as soon as possible."
A number of Alliance Party offices have been attacked following the decision to restrict the number of days the Union flag flies over Belfast City Hall at the end of last year.
The office belonging to Alliance MLA Stewart Dickson in Carrickfergus was destroyed by arsonists in December.
The party's only MP, Naomi Long, and a number of local councillors were the recipients of death threats - others had their homes attacked.
To date, the cost of policing the flag dispute in Northern Ireland stands at £20m, with over 210 arrests linked to public disorder made.