Visual categorization is the brain ability to rapidly and automatically assign a visual stimulus to a given category despite more or less ambiguous inputs. Whether visual categorization can be mediated by non-visual inputs, such as odors, to resolve ambiguity, remains poorly understood. Here we test the influence of odor contexts on category-selective neural responses, expecting that congruent odors facilitate the categorization of ambiguous visual inputs. Scalp electroencephalogram (EEG) was recorded in 26 participants while natural images of various objects were presented at 12 Hz (i.e., 12 images / second). Variable exemplars of a target category were interspersed every 9 stimuli to tag category-selective EEG responses at 12/9 = 1.33 Hz. The target category was either unambiguous (2 categories: human faces and cars) or ambiguous (facelike objects perceived either as nonface objects or faces). Odor contexts (body, gasoline or baseline odors) were diffused implicitly during visual stimulation. We identify clear category-selective responses to every category over the occipito-temporal cortex, with the largest response for human faces and the lowest for facelike objects. Importantly, body odors enhance the neural response to the ambiguous facelike objects, especially for participants reporting the perception of an illusory face in these stimuli. In contrast, odors do not modulate other category-selective responses, nor the general visual response recorded at 12 Hz, revealing a selective facilitating influence on the visual categorization of congruent ambiguous stimuli. Overall, these observations demonstrate that the human brain actively uses cues from the other senses to readily categorize ambiguous visual inputs, and that olfaction, which has long been held as poorly functional in humans, is ideally suited to disambiguate visual information.