There is no gainsaying that individuals with diverse sexual orientations and gender identities are faced with serious socio-legal, and medical discrimination following the enactment of anti-homosexuality law in Nigeria. However, not much is known of the effort of an organized body of psychology in the country to ensure adequate knowledge and competence among Nigerian psychologists. This article, therefore, appraises the stance of Lesbian, Gay, Bisexual, and Transgender (LGBT) psychology in Nigeria in relation to the cardinal quadrants: Advocacy, Education, Research, and Practice. A multi-method design was adopted to sort for both primary and secondary data. Purposive sampling was adopted to involve 124 practicing psychologists. Findings revealed that the Nigerian psychology curriculum limits its scope to sexual and gender disorders (sexual dysfunction, gender dysphoria, and paraphilic disorders) while missing out on sexual and gender diversity content. Furthermore, the outcome shows that not much is documented on the contribution of the field of psychology to the knowledge of LGBT. Many of the participants had a history (and still) working with LGBT clients and did not have formal LGBT-affirmative training. The study concluded that the integration of LGBT psychology is essential for significant achievement in the space of advocacy, education, research, and professional practices.