Background: Whilst the overall proportion of young people drinking alcohol in the United Kingdom has decreased in recent years, those who do drink appear to drink a larger amount, and more frequently. Early and heavy drinking by younger adolescents is a significant public health problem linked to intellectual impairment, increased risk of injuries, mental health issues, unprotected or regretted sexual experience, violence, and sometimes accidental death, which leads to high social and economic costs. This feasibility pilot trial aims to explore the feasibility of delivering brief alcohol intervention in a school setting with adolescents aged 14 and 15 and to examine the acceptability of study measures to school staff, young people and parents.Methods and design: Seven schools across one geographical area in the North East of England will be recruited. Schools will be randomly allocated to one of three conditions: provision of an advice leaflet (control condition, n = 2 schools); a 30-minute brief interactive session, which combines structured advice and motivational interviewing techniques delivered by the school learning mentor (level 1 condition, n = 2 schools); and a 60-minute session involving family members delivered by the school learning mentor (level 2 condition, n = 3 schools). Participants will be year 10 school pupils (aged 14 and 15) who screen positively on a single alcohol screening question and who consent to take part in the trial. Year 10 pupils in all seven schools will be followed up at 6 and 12 months. Secondary outcome measures include the ten-question Alcohol-Use Disorders Identification Test. The EQ-5D-Y and a modified short service use questionnaire will inform the health and social resource costs for any future economic evaluation.Young people recruited into the trial will also complete a 28-day timeline follow back questionnaire at 12-month follow-up. A qualitative evaluation (with young people, school staff, learning mentors, and parents) will examine facilitators and barriers to the use of screening and brief intervention approaches in the school setting in this age group.