The first hearings take place in Edinburgh on Wednesday and are expected to last several weeks.
Faith based organizations as well residential and foster care providers are due to give evidence as well as expert witnesses, the Scottish Government and survivors.
It will cover a period within living memory of anyone who suffered such abuse, no later than 17th December 2014.
The inquiry aims to establish to what extent institutions and bodies with legal responsibility for the care of children failed in their duty to protect children in care in Scotland, as well as seek to identify any systemic failures in fulfilling that duty.
As well as the Church of Scotland, the Benedictines, The Good Shepherd Sisters, Quarriers, Barnardos and Aberlour Child Care Trust will also give evidence.
So far, the inquiry has received criticism as its original chairwoman Susan O'Brien QC resigned from the post in 2016 after citing government interference - something which the government at the time rejected. A second panel member, Prof Michael Lim, also resigned claiming that the inquiry was doomed.
The new chairwoman Lady Smith (pictured) - who was appointed to the role in 2016 - said: "We are determined to find out what happened, where, how and why, what was the conduct and what were the failings of institutions and others entrusted with the care and protection of children."