Relationships and Sex Education (RSE) in schools are predominantly heterocentric. Consequently, lesbian, gay, bisexual, transgender, and questioning young people have reported feeling excluded. This exclusion results in feelings of being "different" and "other," which in turn leads to further disengagement in the sex education classroom, contributing to poor sexual health literacy, greater risk of abusive relationships, and higher rates of sexually transmitted infections. A rapid review was undertaken to identify the impact of non-inclusive sex education. The review makes recommendations for policy and practice, which includes the provision of training courses to school teaching staff with an emphasis on inclusive RSE, appropriate online resources for lesbian, gay, bisexual transgender, and questioning (LGBTQ) young people, as well as offering 1:1 emotional health support for LGBTQ young people as they begin to question their sexual orientation.