HM Inspectorate of Constabulary in Scotland (HMICS) will carry out a review while the Scottish Police Authority (SPA) will undertake a "scrutiny inquiry" of the practice.
A small number of officers throughout Scotland were given a standing authority to carry guns following the merger of the old eight forces.
Opposition parties said this amounts to a change in the culture of policing and should have been debated in Parliament.
The HMICS review will independently assess current practices for the issue and carrying of firearms by armed response vehicle (ARV) crews under the standing authority.
The SPA inquiry will consider the public impact of Police Scotland's decision around firearms deployment.
Derek Penman, HM Inspector of Constabulary in Scotland, said: "This review provides an opportunity for HMICS to make an objective professional assessment on whether the operational decision-making by Police Scotland on the standing authority for firearms has followed the relevant guidance, and that any conclusion is supported by the prevailing threat, risk, and available intelligence.
"This assurance role was requested by Police Scotland, but this will be an independent review with the remit and scope that we have assessed is necessary to fulfil our objective to add value and strengthen public confidence in policing."
The HMICS review will be provided to the SPA in time for consideration on October 29.
The SPA inquiry will then draw together its own evidence and that of the HMICS review, and report with overall findings and recommendations on December 17.
Iain Whyte, chairman of the SPA scrutiny inquiry, said: "Questions and views continue to be raised about the issue and we have concluded that an inquiry provides an opportun-ity for us to assess the level and nature of those concerns."
Police Scotland welcomed the announcements.
Deputy chief constable Iain Livingstone said: "Following this review and if a decision is made that the authority should remain in place, we will commission further work to consider alternative options for the carrying of weapons by armed officers.
"Police Scotland will also review the operational guidance provided to officers."