Chivenor, formerly a Royal Air Force station, will remain as home to the Commando Logistics Regiment and 24 Commando Royal Engineers.
Norton Manor Camp will remain home to 40 Commando Royal Marines.
Mr Ellwood finished by saying the objective has been to "strike the right balance between working with the community, achieving value for money for the taxpayer and making sure our Armed Forces have what they require to protect our people".
"I believe our Defence Estates Optimisation Programme is getting that balance right and that we are on track to create the world-class bases our nation needs," he said.
In response, Labour's shadow defence secretary Nia Griffith wanted to make sure the closures would not effect recruitment, "particularly for reservists who obviously rely on facilities being within a reasonable travelling distance of where they live".
Mr Ellwood said the issue is "on the forefront of our mind" when making these decisions, adding he did not want to lose reservists and cadets because of this process.
He also pledged the 3 Commando Brigade would remain in Plymouth after fears the unit could be moved outwith the city when it leaves its "spiritual home" at Stonehouse Barracks.
The closures were originally announced in November 2016, as part of the government’s 'better defence estate' plan, which identified 56 defence sites to be vacated and sold.
Video: James Hirst looks at the Government's announcement of delays to the closure and sale of other military bases.
At the time, then-Defence Secretary Sir Michael Fallon told Forces News all decisions had been taken on the basis of military advice and that the majority of funds generated from the sales would go towards new and modern accommodation.
The plan was to cluster the Royal Marines at Devonport Dockyard in Plymouth and across the River Tamar at HMS Raleigh in Torpoint.
It was part of an overall strategy designed to bring military jobs and families into more urban areas, in part to help forces wives and husbands looking for their own employment.
However, local opposition to the Chivenor and Norton Manor has been strong, and local MPs have repeatedly pushed parliament for reprieves.
Thursday's announcement is accompanied by the confirmation that £1.5 billion will be invested across the country over the next five years to ensure that the estate meets both military requirements and the high standards required to house and support service personnel and their families.
It is part of the £4 billion committed in 2016 in the better defence estates strategy to improve and upgrade defence sites.