International literature suggests that gender-diverse people are at increased risk of thoughts and acts of self-injury compared to their cisgender peers. The current review aimed to investigate the prevalence of self-injurious thoughts and behaviours (SITBs) among children and young people (CYP) in the United Kingdom identifying as a gender not typically associated with the sex they were assigned at birth and, further, to examine relevant prevalence rates of SITBs reported both in academic and grey literature. In total, seven studies were included in the review and indicated an increased prevalence of SITBs among gender-diverse CYP compared to the general population. However, methodological limitations and significant heterogeneity in the rates of SITBs reported require that the available literature be interpreted with some caution. Important factors to consider when interpreting SITB rates, as well as recommendations for future research, are discussed.