<p>The concept of sustainability capital has been gaining momentum worldwide, and companies are encouraged to report on sustainability capital in their integrated reports. Companies are now starting to shift their focus from reporting only quantitative factors to including qualitative factors. The model shifts attention from short-term profits to sustainable growth. However, as demonstrated by a large body of equivocal literature with deep roots in the field of study, the effect of sustainability capital on companies’ profitability has become a crucial concept in current discussions of sustainable development. This study examined the effect of sustainability capital on the profitability of companies listed on the Johannesburg Stock Exchange. This study adopted a quantitative approach to generate secondary data sourced from the integrated annual reports of 20 top-performing mining and manufacturing companies that were purposively sampled and listed on the Johannesburg Stock Exchange (JSE) for the years 2011–2021 using content analysis. The secondary data were analysed using Feasible Generalized Least Squares (FGLS). The findings of the study indicate that Social and Manufactured capitals have a positive relationship with return on assets, while natural, financial and human capitals have a negative relationship with return on assets. In the competitive market of South African mining and manufacturing firms, this study highlights the value of sustainability practices and emphasises the necessity of developing and leveraging sustainability capital to improve companies’ performance and competitiveness. It offers a valuable tool for enhancing company performance and a fresh perspective on sustainability capital.</p>