This study aims to explore social reporting by Islamic banks (IB) (referred to as Islamic social reporting, ISR, hereafter) through two streams, i.e., its determinants and consequences on firm performance. Using annual report data from 90 samples of the world’s IB from 2016–2020, this study focuses on the sharia governance implementation through the role of the Sharia Supervisory Board (SSB). The SSB was measured by individual characteristics and IG-Score, representing a combination of dichotomous characteristics of the SSB, which have not been encountered in previous studies. Firm performance as a consequence of disclosure was determined by a more comprehensive approach based on accounting and the stock market. The study’s findings demonstrate the SSB’s beneficial influence on ISR, suggesting that the presence of an SSB can promote ISR practices. Social reporting has been found to have a negative impact on ROA, but it has a positive impact on MTBV and Tobin’s Q. The data suggest that while voluntary reporting practices may cause a short-term decline in profitability, they can have a positive impact on an enterprise’s long-term value.