The biggest school in the Highlands - Inverness Royal Academy - is to become a "no-phone zone" from next February.
In a message to pupils and parents, the school said some children were using their phones during lessons and others to record fellow students and sometimes staff without their consent.
Pupils are to be asked to leave their devices at home or keep them switched off.
Exceptions are to be made, including for children who need their phones for medical reasons.
Inverness Royal Academy has a roll of about 1,350 pupils.
Highland Council said its schools agreed policies on the use of phones with their communities.
It added that under devolved school management, each school could implement mobile phone policies to "match the context of their individual setting".
In September, the local authority said dozens of its schools were working towards taking a position on whether or not to ban pupils' use of mobiles in classrooms.
In a report, officials said at the time that 10 schools expected to make a decision during the first term of 2025-26.
A further 23 planned to consult on phones at some point during the 2025-26 session.
The report said two other schools were already holding community consultations.
Pupils at two high schools in Edinburgh were asked to keep their mobiles in lockable pouches during the day under a phone-free policy introduced in May.
Students at Portobello High School and Queensferry High School were issued with special wallets which, once sealed, require a magnetic pad to unlock them.
Pupils are allowed to keep their phones in their possession but expected to keep them in the pouches until the bell rings at the end of their final lesson.
Edinburgh Council's education convener said at the time that the move would end the "competition" between phones and teachers for pupils' attention.
In August, Education Secretary Jenny Gilruth said headteachers across Scotland were trusted to take the best decisions in the interests of their school communities.
Western Isles councillors agreed to a new policy on pupils' use of mobile phones and tablets in the islands' schools in November.
The devices are to be banned during class-time in the isles' four secondaries, unless permitted by teachers for educational purposes.
In primary schools, children are to be discouraged from taking their phones or tablets.
Councillors agreed there could be potential exceptions to this rule and these should be taken into consideration in individual cases.