The first fire chief of the new national service is to be named.
It follows a decision to merge the existing eight regional forces in a major shake-up of fire and police in Scotland.
The post will be announced at Perth community fire station, which will serve as the interim headquarters of the new brigade when it takes over on April 1 next year.
The Scottish Government said the single police and fire services will save £1.7 billion over 15 years.
Legislation to merge the regions was given the royal seal of approval last week.
The Police and Fire Reform (Scotland) Act 2012 was opposed at Holyrood by Liberal Democrat and Green MSPs, who are concerned the Government will centralise and politicise the police.
Recruitment is under way for a chief constable for the new national police force.