Liquidity performance of firms is believed to be influenced by several financial and non-financial factors. Scholars also argued for the interaction between this and the sustainability reporting activities of companies, including emerging economies like Nigeria and South Africa. The argument on this interplay elicited the aim of this research. This study assessed the nexus between sustainability reporting disclosure and liquidity performance of firms in Nigeria and South Africa, using statutory responsibilities (Big4 audit firm and tax liability) as the moderating variable. Ex post facto research design was utilized with data obtained from audited financial statements of the relevant firms covering 2012–2023. Census sampling was used as the sampling technique. Pooled OLS regression was utilized. Also, a t-test was used to compare both Nigeria and South Africa. The results showed that governance disclosure had a positive but insignificant effect, while economic and environmental disclosure had a negative and significant effect on current ratio. On the other hand, governance disclosure had a positive and significant effect while environmental disclosure had a positive and insignificant effect on working capital intensity. Likewise, economic disclosure had a negative but significant effect on working capital intensity. The findings also revealed a positive and significant relationship between the moderating effects of Big4 audit firms and tax liabilities on explanatory variables. The results imply the existence of a statistical correlation between sustainability reporting disclosure and liquidity performance. The study recommends improved transparency in sustainability reporting disclosure to increase investors’ confidence, which would translate to better liquidity performance.