The development of teacher competence has been essential throughout history because the quality of every education system depends on the quality of its teachers. This study investigated the relationship between instructional supervision and teacher competence enhancement in secondary schools in Greater Arua, Uganda. Specific objectives were to examine the relationship between directive, collaborative and non-directive supervision and teacher competence enhancement in secondary schools in Greater Arua. The study hypothesised that there was no statistically significant positive relationship between directive, collaborative and non-directive supervision and teacher competence enhancement in secondary schools in Greater Arua, Uganda. The Positivist paradigm and a correlational design were adopted. The population comprised secondary school teachers (n=241) of selected secondary schools in Arua City and Arua District, Uganda. The data collection method was a survey. Study hypotheses were tested using the Pearson Correlation technique. The results revealed a positive relationship between directive supervision (r = 0.144** sig = 0.026), collaborative supervision (r = 0.145*, sig = 0.024) and non-directive supervision (r = 0.161* sig = 0.012, and teacher competence enhancement. The study concluded that all three dimensions of developmental supervision (directive, collaborative and non-directive) have a positive relationship with teacher competence enhancement. As a recommendation, school-based supervisors should apply a supervisory approach according to the competence level of a teacher. Ministry of Education and Sports should organise regular workshops and seminars for school-based supervisors on the principles of instructional supervision.