Free tampons and other sanitary products will be offered to girls in primary schools from early next year, the Government has announced.
The move comes after Chancellor Philip Hammond's announcement last month of funding for free sanitary products in secondary schools, but campaigners said younger children should also have access to the hygiene products.
Children and families minister Nadhim Zahawi confirmed the scheme, fully funded by the Department for Education, will be extended to include younger schoolgirls.
He said: "No-one should be held back from reaching their potential".
Amika George, who founded the Free Periods campaign more than two years ago, welcomed the news.
She said: "Access to menstrual products for all children in compulsory education will mean that every child can have access to the products they need, and no-one will have to miss school because of period poverty.
"Every child should be able to go to school without wondering where their next pad or tampon will come from, and this will mean that no child will be held back from realising their full potential and being their very best."
In February research from the Bloody Big Brunch revealed more than a quarter of females have missed either work or school because of period poverty.
While it had been previously thought the problem had affected one in 10 women, the survey suggested 27% have at times been unable to afford sanitary products.
Announcing the scheme on Tuesday, Mr Zahawi said: "This Government is determined to ensure that no-one should be held back from reaching their potential - and wants everyone to lead active, healthy, happy lives."
He said: "That is why earlier this year we committed to fully-fund access to free sanitary products in all secondary schools and colleges in England.
"After speaking to parents, teachers and pupils, we are now extending this to more than 20,000 primary schools so that every young person in all our schools and colleges gets the support that they need."
Jo Jones co-founded Beauty Banks, a social enterprise providing everyday essentials like toothpaste, shampoo, deodorant, tampons and sanitary towels, to try help tackle the growing problem.
"If you have to choose between feeding your family or having soap, shower gel and sanitary towels you're obviously going to choose food," she told ITV News.
"We want to be part of a solution for hygiene poverty and period poverty."