Conducted in 2019, this study sought to examine the effect of third party intervention on employee performance on Kampala Capital City Authority (KCCA). Quantitative descriptive cross-sectional survey design was employed in this study. The study targeted 498 technical staff using simple random sampling. Mean and Standard Deviations were used to compute the central tendency and measure of dispersion of conflict resolution and employee performance respectively. Specifically, linear regression analysis was used to determine the effect of the independent variables on the dependent variable. The findings reveal that the effect of third party intervention on employee performance (F=47.245, p=0.000) is significant and confirmed that every unit change in third party intervention would significantly predict a variance in employee performance by 42% (Beta=0.420, p=0.000). It was concluded that third party intervention significantly affects employee performance at KCCA due to the involvement of the third party whom the conflicting parties are well acquainted with hence the best way of resolving conflicts. KCCA management should encourage the use of third party intervention as a form of conflict resolution strategy is a recommendation from this study. It was also advised that the intervening party must maintain a neutral attitude to avoid worsening the problem.