A total of 90 people have been arrested so far as part of the Operation Titan investigation - 66 of whom have been charged while 10 people are being reported to the Public Prosecution Service.
Detective Superintendent Sean Wright said the investigation has received strong support from the public.
"There are people out there who will know the identity of these 18 people who I am looking to speak to. I am confident that those people will come forward with that information," he said.
"It is vital that we all send out a message to those involved in public disorder that such behaviour will not be tolerated. Those who break the law must face consequences for their actions. They will be dealt with appropriately and proportionately through the criminal justice system."
The senior detective also appealed directly to those featured in the images to contact his team.
He added: "I would ask anyone who believes one of the images is of them to contact us immediately in order to help us with our enquiries."
The Operation Titan team are investigating a broad range of offences including the attempted murder of police officers, blast bomb attacks on police, hi-jackings, rioting throughout the Greater Belfast area, breaches of Parades Commission determinations and unlawful protests.
In the east of the city, PSNI came under sustained attack during serious disorder on 12 July.Thirteen officers were injured as golf balls, bricks and fireworks were thrown at police lines.
Anyone who may be able to identify any of the individuals is urged to contact detectives at the Major Incident Room on 028 90 901775 from 9am to 10pm Monday to Friday.