The purpose of this research is to determine the optimal portfolio for manufacturing entities listed on the Indonesian Sharia Stock Index based on a single index model test. The population of this research is manufacturing entities that have been listed in the Indonesian Sharia Stock Index on the Indonesia Stock Exchange for the Period 2019-2020. This study uses a purposive sampling technique using several criteria. Based on this technique, 31 entities meet the criteria. The results showed that the expected return was 5.65%, and the possible risk was 0.22% for 15 (fifteen) stocks included in the optimal portfolio category.