This thesis examines sex education in the UK. The project presents an account of current policies and materials in practice, in addition to the primary focus of providing an up-to-date participant account of sex education with specific focus on sexual orientation in English classrooms. This study utilised a multi-method approach comprised of several interlinking parts; a literature analysis of policy and sex education materials, a questionnaire-based survey with sixth form students and interviews/focus groups with LGBT identified young people. These provide a snapshot of current issues surrounding sex education and sexual orientation through experiences in the classroom. It is shown that a public health discourse, at best, guides the topics that are commonly discussed in sex education, both in policy and practice. At worst, it omits various important and contentious issues such as sexual orientation, which are necessary in ensuring a holistic programme. Guidance at the national level is superficial and open to interpretation - this then filters down to the local level which leads to inconsistencies across policies, though it was found that some policies at the local level were both comprehensive and inclusive. While there were classroom materials found to be inclusive of social sex education, these were reportedly not frequently incorporated into the classroom. In the empirical data, young people commonly acknowledged that sexually transmitted infections (STIs) and pregnancy dominated classroom discussions to the detriment and exclusion of other topics identified as important by the participants. This lack of holism contributed to the prevailing notion that sex education was heteronormative, and was perceived to be the result of social inequalities and past political views.