Leaders from 34 schools in Brighton and Hove are to meet to discuss the impact smartphones have on children.
It follows schemes introduced to limit their usage during the school day – including one school that enforced a complete ban due to concerns over safeguarding.
Sarah Raymond, from the campaign group Smartphone Free Childhood, which has organised the conference on Thursday evening, says it is "too important an issue for us to say we can't do anything about it."
However, the group says children with medical conditions that require app usage are exceptions to the rule.