This study applied body chemistry and neuroscience to leadership behaviour. Specifically, it sought to replicate some studies on the relationship between leadership behaviour and happiness. The research method was exploratory because of the paucity of research on leadership behaviour and happiness and involved the use of qualitative and quantitative techniques. The qualitative technique centred on a review and summarisation of existing literature on leadership behaviour, happiness hormones, and happiness on Google Scholars. The quantitative research used a valid and reliable online questionnaire survey on Google Forms to collect information from 80 respondents on different WhatsApp platforms in Canada, the United States of America and Nigeria, selected by judgemenal non probability sampling technique. They were asked if there was a relationship between leadership behaviour and happiness. Six descriptive data analysis methods- tabulation, bar graphs, mode, summations, percentages and average score per respondent - were applied to answer the research question from the coded questionnaire responses. It was found out that there was a relationship between leadership behaviour and happiness. The research also identified the main hormones and neurotransmitters, secreted by mostly the brain, that increase the wellbeing and happiness of leaders and other persons. They are dopamine, oxytocin, serotonin and endorphins (DOSE). It is recommended that leaders should initiate happiness generating activities like kindness, appreciation, team work, praising others, outdoor exercises, get- togethers and handshakes to enhance their leadership behaviours. The researcher also recommended that leadership recruitment, selection, training, evaluation and rewards should be centred on the capacity to generate and distribute happiness. Leaders should be ‘happifiers’ or happiness generators and distributors. Keywords: Body chemistry, leadership behaviour, happiness, dopamine, oxytocin, serotonin, endorphins and happiness.