<p>This study aimed to evaluate the effects of periodontal treatment on periodontal clinical parameters, tongue coating, and olfactory function in non-smoking individuals with periodontitis, and to assess the association between periodontal improvement and changes in olfactory performance. A total of 108 non-smoking patients diagnosed with periodontitis were included. Periodontal status was assessed before and after treatment using the Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), and the Winkel Tongue Coating Index (WTCI). Olfactory function was evaluated using the Sniffin’ Sticks test battery, including odor threshold (T), odor discrimination (D), odor identification (I), and the composite TDI score. Pre- and post-treatment differences were analyzed using the Wilcoxon signed-rank test, with effect sizes calculated using Cohen’s d. Associations between changes in periodontal parameters and olfactory improvement were examined using Spearman correlation and multiple linear regression analyses. After periodontal treatment, significant reductions were observed in PI, GI, PPD, and WTCI scores (<i>p</i> &lt; 0.001). Olfactory assessment revealed significant increases in odor threshold, odor discrimination, odor identification, and total TDI scores following treatment (<i>p</i> &lt; 0.001). Improvements in TDI were significantly correlated with reductions in periodontal parameters, with reduction in PPD emerging as the strongest independent predictor. Periodontal treatment significantly improved olfactory function, with reductions in probing depth emerging as an independent predictor of olfactory recovery, suggesting a potential mechanistic link between periodontal inflammation and olfactory impairment. Periodontal evaluation and appropriate periodontal care could be particular relevance in individuals with olfactory dysfunction and in professions where olfactory performance is critical.</p>