Brenton Tarrant admitted to killing 51 people when he opened fire on two mosques in Christchurch in March of last year.
The 29-year-old Australian is also convicted of the attempted murder of 40 people and a terrorism charge.
The far-right extremist is set to appear in Christchurch court for the four-day sentence amid heightened security.
Police patrols will be increased in the region and mental health specialists will be on hand to help those affected.
It will be the first time that the survivors and the families of the victims, some of whom will be in court, will see him.
” I do not think so [there’s] one day I will not feel the depth of the agony we went through that day, ”said Imam Alabi Lateef Zikrullah, who was at the Linwood Islamic Center when the shooting started.
“I don’t want to see his face. When I see his face, I remember those 51 people. ”
The unprecedented killings have shocked the nation and devastated the local community.
In the attack on March 15, 2019, Tarrant targeted worshipers at the city’s Al Noor Mosque as they gathered for Friday prayers.
After murdering 42 people, he then went to Linwood Islamic Center where he continued his massacre before being arrested by police on a nearby street.
Tarrant issued a manifesto, which he sent to key politicians shortly before the attack began, while also broadcasting the shootings live.
The manifesto and video of the attack were banned by New Zealand authorities.
Prime Minister Jacinda Ardern told reporters the sentencing would be an extremely difficult time for many.
“I don’t think I can say anything that can lessen the trauma that this period is going to be,” she said.
“The whole process will probably take time, it’s as it should be, people need to be heard.
Some of those involved in the case have traveled overseas and had to spend 14 days in quarantine due to the continuing threat of coronavirus.
Over 60 people have provided victim impact statements, which will be part of the hearing.
In order to avoid any further trauma, the judge may prevent the publication of their statements if he sees fit.
Live broadcasting of the proceedings was banned and other media restrictions were also put in place.
Tarrant faces life imprisonment, with a parole release of 17 years.
But the judge has the power to decide whether to jail him without the possibility of release, which means he would spend the rest of his life in prison.
If that happens, Tarrant would be the first person in New Zealand to be sent to prison for their natural life.