<p>This study examined the effect of olfactory stimulation from aromatherapy on creative self-efficacy (CSE) and used electroencephalography (EEG) spectral analysis to explore its neural mechanisms. We hypothesized that olfactory stimuli would influence CSE and that different olfactory stimuli would produce varying effects and accompanying neural activity. College students (<i>n</i> = 168) were randomized into two aromatherapy groups (lavender-sweet orange and peppermint) and one control group (unscented air). Resting-state EEG was collected for 3&#xa0;min, followed by completion of the Self-Assessment Manikin, Chinese Remote Associates Test, Alternative Uses Task, and CSE Scale. The results showed that both the lavender-sweet orange group (<i>p</i> = 0.013) and the peppermint group (<i>p</i> = 0.036) exhibited significantly higher scores on the CSE Scale than the control group. Among the three dimensions of emotion proposed by Mehrabian and Russell’s pleasure-arousal-dominance model, only arousal differed significantly (<i>p</i> = 0.014). However, arousal did not mediate the effect of scent on CSE. Alpha power significantly increased under the lavender-sweet orange condition compared with the peppermint and control conditions. The ratio of (α + β)/(δ + θ) (reflecting the proportion of fast waves to slow waves, indicative of brain alertness) in the frontal and parietal regions was also significantly higher in the lavender-sweet orange group. We also found that, under the lavender-sweet orange condition, CSE was significantly negatively correlated with beta power density. These findings suggest that lavender-sweet orange enhances fast-wave activity, bringing the brain into a state of wakefulness without intense information processing, thereby boosting CSE. However, excessive high-frequency beta excitation suppresses CSE.</p>