More than 250,000 young women are not receiving the support they need to find work, according to a report.
A study showed they faced obstacles, such as unaffordable childcare and transport, that could shut them out of employment.
The Young Women's Trust said 285,000 young women were classed as economically inactive, meaning they are not working or not looking for a job.
Caring for family members was the main reason given by women for being economically inactive, but mothers also struggle to find jobs, said the report.
Young women out of work can feel isolated and struggle to get by financially, according to the charity. It said almost a third of those who are economically inactive want to work.
Some are not eligible for Jobseeker's Allowance because issues such as childcare prevent them from being available for work, the trust said.
Dr Carole Easton, the trust's chief executive, said: "Young women are telling us they want to work but too often they are shut out of the jobs market by a lack of networks and support and a lack of convenient childcare.
"While the Government focuses on reducing its unemployment figures, hundreds of thousands of women who are not included in the numbers are being forgotten.
"The report recommends support and mentoring to help ease young women's transition back into the world of work, access to affordable childcare, better mental health provision and more careers advice and guidance.
"The Young Women's Trust is also calling for a new Minister for Young People to oversee progress.
"Giving young women the support they need to find work will not only help them to become financially independent but will benefit businesses and the economy too."
A Government spokesman said fewer than 5% of young women were unemployed or not in education.
He added: "We're doing more than ever to support families with the cost of childcare by investing a record £6 billion per year by the end of this Parliament, giving working parents up to 30 hours of childcare a week for three and four-year-olds."