The survey of more than 420 teachers and lecturers for the Teacher Support Network, found that the harassment came from both colleagues (68 per cent) and students (47 per cent).
The poll was carried out to coincide with the first same-sex marriage taking place, but found that two-third of teachers feel unprepared for discussing same-sex marriage or LGBT issues in the classroom.
Julian Stanley, chief executive of the Teacher Support Network, said: “For many teachers, their sexuality has resulted in severe levels of discrimination by students but also surprisingly by colleagues as well. This has left some LGBT teachers unable to do their job properly, affected their mental wellbeing and even left them considering leaving the profession altogether. The focus of LGBT policy in schools has tended to be on students, but teachers need to be equally supported.”