Retronasal olfaction plays a crucial role in sensory perception, yet current methods for its assessment remain suboptimal. The ThreeT Retronasal Odor Identification Test was developed to address this methodological gap. Given that cultural differences can influence retronasal olfactory perception, this study aimed to validate the ThreeT test in a Chinese population and explore individual differences underlying test scores. A total of 92 Chinese participants (aged 18–79) completed the ThreeT and the Sniffin’ Sticks Identification Test (SSIT), with a retest conducted after an average interval of 50.5 days. Results demonstrated strong test–retest reliability for the ThreeT (r = 0.83) and sensitivity to age-related olfactory decline, supporting its validity and reliability for retronasal olfactory assessment. Additionally, olfactory function showed meaningful correlations with both affective (State-Trait Anxiety Inventory–Trait; STAI-T) and perceptual (Odor Awareness Scale; OAS-6) measures.