Region-based multi-supply voltage (MSV) design, by which circuits are partitioned into multiple “voltage islands” and each island operates at a supply voltage that meets its own performance requirement, is an effective technique to tradeoff power and performance. Different from conventional voltage island generation techniques that work in a conservative manner to guarantee “always correct” computation, in this work, we investigate the MSV design problem for timing-speculative circuits, which achieves high energy-efficiency by allowing the occurrence of infrequent timing errors and correcting them online. A novel algorithm based on dynamic programming is developed to tackle this problem. Experimental results on various benchmark circuits demonstrate the effectiveness of the proposed methodology.