Chemical shift-selective fat saturation (CHESS) is the most commonly used fat suppression technique for clinical MRI. Conventional Gaussian-shaped pulses are sensitive to B1 inhomogeneity and their wide transitional band can be affected by B0 off-resonance. Uniform fat saturation across a large field of view (FOV) is especially challenging for body and breast MRI at 3T. Here, we designed a novel frequency-selective RF pulse based on the optimal control theory with robustness to a targeted wide range of B0/B1 conditions. Its superior performance than the regular ones was demonstrated using T1-weighted sequences with whole-breast coverage.