Following recent reports speculating that neither Williams nor Hollins would relocate to Salford, the BBC has revealed that 54% of staff working on the BBC One morning show will not take part in the move to MediaCity UK.
Williams said in a statement: "Sadly, family reasons mean I can't move to Salford with the programme next year.
"My son will be in the middle of A-level exams, another will have just started school and our family also needs to be close to elderly parents in the south-east."
Sports presenter Chris Hollins has also declined to make the move north for family reasons. However, the BBC confirmed that both would continue to be involved with the show "for the foreseeable future".
The show's editor Alison Ford said: "It is great news that lots of the team will be coming to Salford with the programme next year.
"We always knew there would be those who wouldn't be able to make the move for domestic reasons, but we'll have a really strong lineup of producers and presenters working together in MediaCity."
Helen Boaden, director of BBC News, also expressed her delight at the number of staff who had agreed to relocate, adding that she was sure the show would go "from strength to strength" in Salford.
It has also been confirmed that Bill Turnbull and Susanna Reid will stay with the programme.