Pupils starting school in the Western Isles this year will automatically be taught in Gaelic.
The new ‘Gaelic First’ policy has been introduced by the islands council to help boost use of the language and give children the benefits of being bilingual.
The change means the default language of education for the local authority will be Gaelic from P1 until P4, unless parents opt out.
Last year, 47% of P1 children in the area were enrolled in Gaelic Medium Education (GME), with four in ten primary pupils taught in the language.
The most recent census results in 2011 indicated 61% of people in the Outer Hebrides have some understanding of Gaelic and 52% were able to speak it.
Western Isles Council education director Bernard Chisholm outlined the new policy in a letter to teachers and parent councils.
He wrote: “We want to see this number grow in order that we both retain our language and provide all of our children with the many benefits bilingual children gain through the acquisition of another language.”
Mr Chisholm said some parents would need to have the benefits explained in detail and be given information on resources and support available, particularly non-Gaelic speaking families.
In a statement, he added: “The Outer Hebrides is a Gaelic-speaking community, with a rich Gaelic heritage and culture.
“The majority of our children in nursery and those enrolling in primary, want to speak our language.
“A significant number of families, who move to the area without Gaelic, enrol their children in GME for the additional benefits of bilingual education.
“I believe that we all want our children to access the undoubted benefits that GME provides, in both English and Gaelic, in terms of reading, thinking skills, problem solving, maths and in many other areas.
“It is truly a free gift and in this increasingly mobile world, it also enables them to acquire other languages much easier.”