Ms Zelenak, 21, and Ms Boden, 28, were killed when Khuram Butt, Rachid Redouane and Youssef Zaghba drove a van into people walking on London Bridge, then ran through the Borough Market stabbing people with ceramic kitchen knives on the night of June 3, 2017.
Canadian Christine Archibald, 30, Briton James McMullan, 32, Frenchmen Xavier Thomas, 45, Alexandre Pigeard, 26, and Sebastien Belanger, 36, and 39-year-old Spaniard Ignacio Echeverria also died in the attack.
All but Mr Thomas, who was hit by the van and thrown into the Thames River, are believed to have been stabbed to death.
Another 48 people were injured in the violence, while all three attackers were shot dead by police at the scene.
The inquest is expected to start at the Old Bailey in London on Tuesday morning local time.
Queensland nanny Ms Zelenak evaded two previous terror attacks; she had a ticket to the Ariana Grande concert that was bombed in Manchester but didn't go, and was at Westminster Bridge a day before a deadly rampage three months before the London Bridge attack.
Her mother Julie and stepfather Mark Wallace, who started holistic trauma healing centre Sarz Sanctuary after her death, have reportedly flown to London for the inquest at the Old Bailey on Tuesday.
The pair have already been told by London police most of the details about what happened that night.
"It's certainly that process to identify learnings of how it can change or be better and make cities safer," Mr Wallace told the ABC.
South Australian nurse Ms Boden, who worked at the Guy's and St Thomas' Hospital, posthumously won two bravery awards as she was killed while trying to help other victims.
She was honoured by the Queen by being named on the 2018 Civilian Gallantry list and was also awarded the Australian Bravery Medal two months ago.
Ms Boden had been having dinner with two friends when they heard a commotion and she jumped up immediately and ran towards the bridge to see if anyone was hurt, the citation from the governor-general's office said.
"Moments later, the area turned to a scene of mass chaos and panic as people began screaming and running from the bridge into Borough Market. Ms Boden's two friends lost sight of her in the melee.
"As soon as they were able, they made their way back to where they thought Ms Boden would be. They located her on the pavement about 50 metres away from the restaurant. She had been attacked and severely wounded by terrorists who had been in the van, and a police officer was performing CPR on her."
Ms Boden has been dubbed 'the angel of London Bridge' for her actions that night.
The inquest is expected to run for about eight weeks.
