There were audible gasps in court as Justice Baker jailed Hashem Abedi for life on each of the 22 counts of murder he was convicted of.
"The defendant should clearly understand the minimum term he should serve is 55 years. He may never be released," he said.
Twenty-two people were killed in May 2017 when Salman Abedi detonated a bomb as people were leaving an Ariana Grande concert at the venue.
Hashem Abedi, seen in an undated photo, was extradited from Libya and arrested in London after the attack. (Force for Deterrence in Libya via AP)
He died in the attack, while hundreds of others were injured.
In March, his brother Hashem was found guilty by a jury of 22 counts of murder, attempted murder and plotting to cause an explosion likely to endanger life.
He helped source, buy, stockpile and transport the components for his brother's bomb, the court heard, using a number of phones, vehicles and addresses in preparation for the attack.
Hashem, who went to Libya the month before the bombing, was arrested hours afterwards and extradited back to Britain last summer, telling police he wanted to cooperate.
The grieving families gave emotional evidence at the Old Bailey on Wednesday, as Justice Baker began sentencing the homegrown Islamic State-inspired jihadi.