Early-career constables Matthew Arnold (26) and Rachel McCrow (29) were shot dead on a property at Wieambilla, west of Brisbane, on December 12.
The Arnold and McCrow families paused for a moment at the coffins at the front of the service at the Brisbane Entertainment Centre on Wednesday morning.
Thousands of mourners packed into the building to attend the memorial along with Prime Minister Anthony Albanese, Opposition Leader Peter Dutton, Queensland Police Commissioner Katarina Carroll, Premier Annastacia Palaszczuk, state Opposition Leader David Crisafulli and Governor Jeannette Young.
Constable Keely Brough, who was with constables Arnold and McCrow when they were killed, fought back tears as she sat in the crowd of her colleagues in blue.
The ceremony was broadcast live in a number of public places around Queensland, including in the communities of Tara, Dalby, Chinchilla and Miles near the site of the tragedy at Wieambilla, three hours west of Brisbane.
Private funeral services will be held later.
Ms Carroll has said the two constables didn't stand a chance when they came under fire alongside two other officers, Constables Bough and Randall Kirk, at the property.
They had gone there as part of a missing persons check and were met by a hail of gunfire fired by Gareth Train, his wife Stacey and his brother Nathaniel.
Neighbour Alan Dare was also killed when he went to check on a fire lit to flush out Brough as she took cover in the bush.
Speaking ahead of the service, former police officer John O'Gorman said he was still in shock about the deaths, which he heard on the radio while he was driving.
"I had to stop, I got very emotional I was extremely angry, still am, and ... the people who want to criticise the police for what they do, want to stop and have a look at what police do, they die protecting the community," he told 6News.
The shooters died in a firefight with specialist officers several hours after the four constables first arrived at the scene.
Investigators are yet to officially declare a motive but are examining known links between the Trains and extreme conspiracy theorist groups and forums.
