Control‐related cognitive processes are associated with cortical oscillations and modulated by catecholamine neurotransmitters. It remains unclear how catecholamine systems modulate control‐related oscillations. We tested modafinil effects on rule‐related 4–30 Hz oscillations, with double‐blind, placebo‐controlled (within‐subjects) testing of 22 healthy adults, using EEG during cognitive control task performance. EEG data underwent time‐frequency decomposition with Morlet wavelets to determine power of 4–30 Hz oscillations. Modafinil enhanced oscillatory power associated with high‐control rule selection in theta, alpha, and beta ranges, with a frontotemporal topography and minimal effects during rule maintenance. Augmentation of catecholamine signaling enhances middle‐frequency cortical oscillatory power associated with rule selection, which may subserve diverse subcomponent processes in proactive cognitive control.