The main objective of this study is to propose a linked simulation–optimization approach for solving aquifer parameter estimation problems from pumping test results. In the simulation part of the proposed approach, the drawdowns at given monitoring points and times are calculated by considering the Theis and Hantush approaches for confined and leaky confined aquifers, respectively. This simulation part is then integrated to a newly proposed hybrid optimization approach, namely DE–Solver, which integrates the differential evolution (DE) algorithm and generalized reduced gradient (GRG) method of the spreadsheet Solver add-in. The performance of the proposed approach is evaluated by considering two pumping test data for confined and leaky confined aquifers. Identified results indicate that the proposed approach provides better results than those obtained by using different approaches in the literature.