The commissioner has been named as Malcolm Newsam, who has previously been drafted in as commissioner to help improve children's services in Rotherham and Sandwell. His appointment follows a highly critical Ofsed report into the quality of child protection services in Northamptonshire.
Among Newsam's priorities is to review how children's services in the county can best be run should the proposed restructure be implemented.
The Ministry of Housing, Local Government and Communities has launched a consultation on plans to replace the county's current two-tier system, of a county council and district and borough councils, and create two single-tier authorities. If approved, the two new authorities - covering the west and north of the county - would come into being on 1 April, 2020.
The government has said restructuring is needed due to financial problems the county council has faced this year. The local authority is looking to make £70m worth of savings and is subject to a Section 114 notice, banning it from any new spending outside of children's and adult social care.
A DfE directive released this week states that Newsam's review will look at "the most effective way of delivering children's services in Northamptonshire should the Secretary of State for Housing, Communities and Local Government decide to implement a proposal for reorganisation of local government in Northamptonshire".
He will also assess "the pace, progress and sustainability of improvements to children's services" following the focused check by Ofsted in October.
Inspectors said there had been a significant deterioration of services over the past two years and warned of rising caseloads for social workers that were leaving children unprotected. At its last full inspection Northamptonshire was rated "requires improvement", after previously being graded "inadequate" in 2014.
Northamptonshire County Council had previously been handed £4m from the DfE's Children's Social Care Innovation Programme to help launch an independent trust to run children's services.
A limited company, called Children's First Northamptonshire, was set up to develop the new organisation ahead of a planned launched next year. However, in August it emerged that the plans had been shelved due to uncertainty around the future of the council.
Northamptonshire County Council has been contacted for comment.