Damien Gibson, 36, pleaded guilty in the Victorian County Court to culpable driving causing the death of Olivia Stevens on September 11, 2021.
Olivia was one of seven children, all aged under 10, who were passengers on Gibson's all-terrain vehicle when it rolled on a farm at Rosedale in Victoria's Gippsland region.
The six-year-old was critically injured in the crash and died after being flown to the Royal Children's Hospital in Melbourne.
The six other passengers survived, including Gibson's five children.
In sentencing Gibson on Thursday, Judge Richard Maidment noted none of the children were wearing helmets or seatbelts.
"The consequences of your negligence are tragic," the judge said.
"The death of their beloved daughter, sister and granddaughter have been, and will continue to be, utterly devastating," he said of the victim's family.
But the offending fell at the lower end of seriousness for culpable driving and Gibson had shown remorse through his guilty plea, Judge Maidment said.
Gibson was jailed for five years but will be eligible for parole in just over two years, having already served nearly eight months behind bars.