Ms Green replaces Rebecca Long-Bailey, who was sacked by Labour leader Keir Starmer on Thursday.
In April, the Labour leader had made Ms Green shadow minister for child poverty strategy.
Elected an MP in 2010, Ms Green also served as shadow minister for disabled people under Ed Miliband from 2013 to 2015.
Labour leader Keir Starmer said, ‘I’m delighted to appoint Kate Green as shadow education secretary. Kate has spent a lifetime campaigning against child poverty and educational inequalities. I look forward to working with her in this new role.’
Ms Green added, ‘It’s a privilege to have been asked to serve as shadow education secretary. The coronavirus epidemic has had a devastating impact on children’s education. I look forward to working with teachers, unions, parents and councils to help ensure we get our children back in school as soon as possible.’
Before her election in 2010, Ms Green was chief executive of the Child Poverty Action Group. Prior to this, she was director of the National Council for One Parent Families, now known as Gingerbread.
She is a long standing campaigner against poverty and inequality, is a member and former chair of the all-party parliamentary group on poverty, and served as a member of the Greater Manchester Poverty Commission. In 2013 Kate was appointed an ambassador for the Albert Kennedy Trust, a charity which supports LGBT homeless young people in crisis.