Background: Despite a large body of research that has explored the influence of genetic and environmental factors on educationally relevant traits, few studies have explored teachers' beliefs about, or knowledge of, developments in behavioural genetics related to education. Aims: This study aimed to describe the beliefs and knowledge of UK teachers about behavioural genetics and its relevance to education, and to test for differences between groups of teachers based on factors including years of experience and age of children taught. Sample: Data were gathered from n = 402 teachers from a representative sample of UK schools. Teachers from primary and secondary schools, and from across the state and independent sectors, were recruited. Methods: An online questionnaire was used to gather demographic data (gender, age, years of experience, age of children taught, and state vs. independent) and also data on beliefs about the relative influence of nature and nurture on cognitive ability; knowledge of behavioural genetics; openness to genetic research in education; and mindset. Data were analysed using descriptive statistics, ANOVA, correlations, and multiple regression. Results: Teachers perceived genetic and environmental factors as equally important influences on cognitive ability and tended towards a growth mindset. Knowledge about behavioural genetics was low, but openness to learning more about genetics was high. Statistically significant differences were observed between groups based on age of children taught (openness higher among primary teachers) and state versus independent (more growth-minded in state sector). Conclusions: Although teachers have a limited knowledge of behavioural genetics, they are keen to learn more.