Simon Riley Principal of Caedmon College in Whitby, is leaving his post at half-term "due to personal reasons", says the school's chair of governors.
But a Facebook group has been launched this week entitled Save Our Head Mr Simon Riley, which has already attracted more than 230 members.
Its administrator is urging people to contact North Yorkshire County Councillors, MP Robert Goodwill and Education for Education Gavin Williamson.
Chair of Governors Pen Cruz said: "Simon Riley has achieved a huge amount over the three years he has been with us and we are sorry that he will be stepping down from his position as Principal of Caedmon College in Whitby at half-term, due to personal reasons.
“Simon has been popular with students, staff and parents and worked closely with them on all aspects of school life.
"We know that the great support he has given students will be very much missed and we will all be sad to see him go.
“The governors would like to thank Simon sincerely for his hard work and achievements and wish him well for the future.
“We are now in the process of selecting an interim headteacher and would like to assure parents and pupils that our focus will remain on students’ wellbeing and education during this time.”