Deviations from heteronormativity affect labour market dynamics. Hierarchies of sexual orientation can result in job dismissals, wage discrimination, and the failure to promote gay and lesbian individuals to top ranks. In this paper, I report on a field experiment (144 job-seekers and their correspondence with 5,549 firms) that tested the extent to which sexual orientation affects the labour market outcomes of gay and lesbian job-seekers in the United Kingdom. Their minority sexual orientations, as indicated by job-seekers' participation in gay and lesbian university student unions, negatively affected their workplace prospects. The probability of gay (lesbian) applicants receiving an invitation for an interview was 5.0% (5.1%) lower than that for heterosexual male (female) applicants. In addition, gays (lesbians) received invitations for interviews by firms that paid salaries that were 1.9% (1.2%) lower than those paid by firms that invited heterosexual male (female) applicants for interviews. In addition, in male- (female-) dominated occupations, gay men (lesbians) received fewer invitations for interviews than their non-gay (non-lesbian) counterparts. Furthermore, gay men (lesbians) also received fewer invitations to interview for positions in which masculine (feminine) personality traits were highlighted in job applications and at firms that did not provide written equal opportunity standards, suggesting that the level of discrimination depends partly on the personality traits that employers seek and on organisation-level hiring policies. I conclude that heteronormative discourse continues to reproduce and negatively affect the labour market prospects of gay men and lesbians.