The performance of quoted firms listed on the Nigerian Exchange Group (NGX) is crucial for driving economic development, job creation, and wealth generation in Nigeria. Despite the growing interest in sustainability practices among Nigerian firms, there is a lack of empirical research examining the relationship between sustainability reporting and financial performance. To address this gap, this study conducted a comprehensive analysis of the link between sustainability reporting and the financial performance of quoted firms in Nigeria. This research employed an ex-post facto research approach, utilizing data from annual reports, financial statements, and sustainability reports of 153 publicly listed companies on the Nigerian Exchange Group (NGX). Through quantitative methods, the study assessed the extent and quality of sustainability reporting among Nigerian companies and its relationship with financial performance indicators. A purposive sampling method was used to select a sample of 10 firms known for their voluntary disclosure of information in financial reports. The study spanned from 2012 to 2021, totaling 10 years, and involved both descriptive and inferential statistical analyses of the collected data. Using regression analysis, the study found a statistically significant positive impact of sustainability reporting metrics - including governance information disclosure, credibility information disclosure, and environmental profile disclosure - on firm performance. This suggests that companies in Nigeria that disclose information regarding governance policies, credibility, and environmental practices tend to perform better financially.This study concluded that companies that engage in transparent reporting regarding governance policies, credibility, and environmental practices demonstrate better financial performance. Based on the findings, it is recommended that Nigerian regulators and policymakers encourage and support sustainability reporting initiatives among quoted firms.