The purpose of this study was to examine the effect of Organization Design on employee performance in Bank of Uganda, centering on three elements of Organization Design that is, Organizational Structure, Rewards and Organizational Culture. The study adopted a correlational research design, since it sought to establish the relationship between Organization Design (Organizational Structure, Rewards and Organizational Culture) and employee performance. The study was also descriptive in nature since it sought to describe characteristics of a group of employees in Bank of Uganda. The sample size was 201 staff of Bank of Uganda out of an accessible population of 247. The data were collected through questionnaires which were statistically analyzed through descriptive, correlation and regression analyses. Qualitative data were obtained through interviews and open-ended questions in the questionnaires. The study found that organizational structure, rewards and organizational culture were all positively and significantly related to employee performance. It was therefore concluded that any improvement in organizational structure, rewards or organizational culture would lead to an increase in employee performance in Bank of Uganda and vice versa. The key recommendations are; Bank of Uganda should enhance its organizational structure, rewards and organizational culture simultaneously in order to improve performance of employees. The organizational structure should be modified, so that it is flexible enough to support employee involvement, allow more decision-making at lower levels, and encourage creativity and innovativeness. Bank of Uganda should also improve its rewards by revising its policies on promotion, training and recognition and also introducing performance-based pay. Lastly, Bank of Uganda should conduct leadership/ management assessments, in order to identify areas that require improvement, and provide training and development plans focusing on the specified areas. Management practices that encourage employee engagement should also be reexamined to further improve employee performance.