In two experiments we address an ongoing debate concerning the processes driving context-driven modulations to the Stroop effect (Crump, Gong, & Milliken, 2006). In particular, we demonstrate that context-driven processes can modulate the size of the Stroop effect for frequency-unbiased item types. We also clarify the role of item frequency in producing context-driven modulations to the Stroop effect. Taken together, our results provide unambiguous support for the claim that contextual processing can impart fast and flexible control over the operation of selective attention processes during online performance.