Department for Education figures have shown a 78% increase in youngsters placed in children's homes out of their borough.
The number went up from 2,250 in 2012 to 4,020 in 2016.
Chair of the All Party Parliamentary Group on Missing Children and Adults, Ann Coffey, said the latest figures were ‘bitterly disappointing,' particularly as they come four years after the Government said it would reduce the numbers.
Ms Coffey warned children placed in homes outside their local authority areas were ‘at high risk of going missing and coming to harm'.
She said: ‘There are additional difficulties in keeping children safe when they are placed away from their local area.'
Director of policy and research at The Children's Society, Sam Royston, said: ‘Children in care are some of the most vulnerable in society and should only be placed outside of their home local authority area if it is necessary to keep them safe and well.
‘However, we know that in many cases children are being placed far from their family and friends because there are not enough appropriate placements in their local area.
‘When children are placed in either residential care or foster placements some distance from home they are more likely to go missing from home with all the risks that brings – including child sexual abuse and other types of exploitation.'
Mr Royston urged councils to do ‘much more' to ensure every placement is in the ‘best interests' of the child and that they are well supported if they are moved away from their home area.
Chief executive of Action for Children, Sir Tony Hawkhead, said: ‘Where children have to be placed out of area, information must be shared between agencies across local authority boundaries with thought given to how children can maintain existing links and nurture key relationships with those they care about at home.
‘With such a staggering national increase in children being placed in homes out of their area, government must ensure more than ever that this process is being carried out to meet the welfare and needs of each child.'