Hundreds of serving and former police, political leaders and family members gathered beside Lake Burley Griffin as part of National Police Remembrance Day services across Australia and the south-west Pacific Region on Tuesday.

A dawn service in Queanbeyan and evening service at King's Park were held to remember the 757 fallen police officers enshrined on the National Police Memorial, four of whom were from the ACT.

Mr Turnbull, who attended the service with his wife Lucy, told the crowd the national ceremony was an opportunity to honour the courage and sacrifice of police who served their country and protected their communities.

"Our democracy depends on many things. But none is more important than the daily heroism and commitment of the police forces of our nation.

"Because every day, you and your many comrades, your many colleagues in law enforcement across the country, are standing up for democracy ensuring we are safe, ensuring we are a nation ruled by law.

Mr Turnbull remembered the efforts of police who had served abroad in Cyprus, Cambodia, Haiti, Somalia, Timor Leste and the Solomon Islands and said a true democracy "constrains the majority as much as it empowers it".

"It constrains it with the rule of law, and you, your commitment, your courage, ensures that the law is enforced and obeyed."

He said police were "utterly vital" to ensure the nation's continued existence as a free, prosperous, open and democratic society.

Mr Turnbull was joined at the service by ACT police chief Rudi Lammers, Australian Border Force commissioner Roman Quaedvlieg and Attorney-General George Brandis.

Australian Federal Police chief Andrew Colvin said the services marked the most important day on the policing calendar each year and provide the opportunity for solemn reflection.

He said Australian police forces had been fortunate in the past 12 months, with no officers killed in the line of duty.

But he said police stood in solidarity with their colleagues in the Royal Papua New Guinea Constabulary who lost five officers in the past year.

Those names were among seven added to the national memorial this week.

Commissioner Colvin said the devotion police showed to the rule of law, protecting their communities, and serving with courage and integrity often meant they paid "the ultimate sacrifice".

"We thank the Australian men and women currently serving across Australia and overseas and we thank the families who stand by them, so strongly, in their duty.

"For them, as we know, every day is unpredictable. We know that every shift brings a new risk. And we know that for their families, every time they walk back through that door brings a sense of relief."