Islamic banks significantly differ from conventional banks in their adherence to Islamic principles. Therefore, sharia compliance is vital to the sustainability of Islamic banks. In this case, Islamic banks have a Sharia Supervisory Board (SSB) as a special authority overseeing Sharia compliance. Previous studies have explored SSB's characteristics on Islamic banks' performance. However, the influences of cross-member SSB on the performance of Islamic banks by proxy for non-performing financing (NPF) and return on assets (ROA) have yet to be explored. This research examines and analyzes the influence of cross-membership SSB on Islamic bank performance by two proxies, NPF and ROA. The sample in this study consisted of 39 Islamic banks in 9 countries, observed from 2016-2020. The random effect model was used in this research. Based on the test results, cross-membership SSB has a negatively significant effect on NPF and a positively significant effect on ROA