This study analyses the effect of ownership structure and performance of listed conglomerates on the Nigeria Stock Exchange. Over the years manufacturing firms in Nigeria had been faced with liquidity risk, risk of opportunity loss, overcapitalization, undercapitalization, and longer cash conversion cycle. The secondary data used is obtained from six selected manufacturing firms listed on the Nigeria stock exchange for the period of five years 2016-2020. The objective of the study is to analyze the effect of ownership structure and performance. Return on Assets is used as a measure of firm performance while the account receivable days, inventory days, account payables, and total sales are used as measures of ownership structure. The first and third hypothesis is tested using correlation and regression, and the second hypothesis is tested using Analysis of Variance (ANOVA). The study revealed that there is a positive significant relationship between total sales and return on assets and a negative significant relationship between account receivable days, inventory days, account payables, return on assets. This indicates that an increase in account receivable days, inventory days, and account payable will lead to a decrease in return on assets and vice versa. Therefore, to meet the firms' objectives, which are to increase profits and create better investor value, an adequate ownership structure should be maintained and each of its different components should be effectively and efficiently managed and controlled.