In our daily lives we rely on prior knowledge to make predictions about the world around us such as where to search for and locate common objects. Yet, equally important in visual search is the ability to inhibit such processes when those predictions fail. Mounting evidence suggests that relative to younger adults, older adults have difficulty retrieving episodic memories and inhibiting prior knowledge, even when that knowledge is detrimental to the task at hand. However, the consequences of these age-related changes for visual search remain unclear. In the present study, we used eye movement monitoring to investigate whether overreliance on prior knowledge alters the gaze patterns and performance of older adults during visual search. Younger and older adults searched for target objects in congruent or incongruent locations in real-world scenes. As predicted, targets in congruent locations were detected faster than targets in incongruent locations, and this effect was enhanced in older adults. Analysis of viewing behavior revealed that prior knowledge effects emerged early in search, as evidenced by initial saccades, and continued throughout search, with greater viewing of congruent regions by older relative to younger adults, suggesting that schema biasing of online processing increases with age. Finally, both younger and older adults showed enhanced memory for the location of congruent targets and the identity of incongruent targets, with schema-guided viewing during search predicting poor memory for schema-incongruent targets in younger adults on both tasks. Our results provide novel evidence that older adults' overreliance on prior knowledge has consequences for both active vision and memory. (PsycINFO Database Record (c) 2020 APA, all rights reserved).