Writing in her monthly commentary, Eleanor Schooling said: "While we are moving in the right direction to support our care leavers, there is still a long way to go."
She cited the difficulty young people face accessing help, particularly mental health support. She added that a lack of career support for care leavers is also an issue and expectations of them remain low.
"For too many, help is offered too late, when they are already in trouble when they have lost all faith in the system," she said.
However, she did highlight a number of cases of good practice in a variety of local authority areas, providing support to vulnerable young people before and after care.
She said local authorities such as Stockton-on-Tees, Cornwall and Durham were good examples of how important it is to establish relationships early between personal advisers and young people in order to stop care leavers "dropping off the end of the system at 18".
Schooling also cited the example of Greenwich, where financial support is provided beyond 18, making it more financially viable for foster carers to support those in their care for longer.
She also emphasised the importance of the Staying Put initiative to support young people to remain in foster care placements beyond the age of 18 so that they can receive continuing support until they are ready to become independent.
The government is trying to boost support for care leavers. However, plans for a care leavers covenant have been delayed. It was due to be launched in time for national care leavers' week in October, but this has been delayed until the new year.
