Currently 855 children are being fostered in Essex and more are waiting to find a loving home. In Herts 745 youngsters currently need help.
The charity says children may find themselves in care because their parent is sick, or they may have experienced abuse or neglect – whatever the reason, they need love, stability and support.
TOWIE (The Only Way is Essex) star Debbie Douglas is supporting Barnardo's campaign as she has fostered more than 250 children.
She said: "Fostering has been one of the most rewarding and fulfilling things I've done in my life. I've had so much joy from watching vulnerable children blossom and thrive when they are in my care.
"I know from being a mum that every child deserves the best start in life. You don't have to have any special skills to foster, just be able to offer a child a loving home."
Barnardo's is reaching out to would-be carers who want to provide homes for older children, siblings, and disabled children. These youngsters often find it more difficult to find homes, increasing the chances they will be moved around or in the case of siblings, tragically, split up.
A Barnardo's South East senior family placement spokesman said: "Loving foster care is crucial to giving vulnerable children the happy home they so desperately need and deserve. However too many never experience this, because there simply aren't enough foster carers to go around to care for the most vulnerable youngsters.
"Single or in a couple, black or white, same-sex or heterosexual; we are asking would-be carers to come forward and help change a child's life."
Since 2010, the number of children in foster placements in England and Wales has risen by eight per cent from 51,250 to 55,745.
To help contact Barnardo's www.barnardos.org.uk/changealife 0800 0277 280.