This study investigated individual differences in language learning traits and intercultural sensitivity among Uzbek first-language speakers learning Korean as a second language(L2) in relation to their attained proficiency. Participants(N = 68) were divided into lower- and upper-proficiency groups according to scores on the Test of Proficiency in Korean. Data were collected from two questionnaires conducted separately over four weeks. The two groups were compared with regards to self-perceived sensitivities to L2 input and preferences in L2 use. Their differences in intercultural sensitivity were compared across three domains: affective, cognitive, and behavioral. The results reveal that advanced learners have greater sensitivities, particularly in lexicogrammatical knowledge, language-related memory, and behavioral adaptation in crosscultural contexts. The affective and cognitive domains of intercultural sensitivity did not vary considerably between the two groups, suggesting that L2 proficiency achievement may not be directly modulated by these factors. The findings suggest that individual differences in linguistic and intercultural sensitivities play a role in L2 development to some extent, but not all constructs are equally influential.