This study examined whether different cognitive correlates are associated with spelling of different target types, such as phonologically consistent and inconsistent syllables, of Korean Hangul among 94 five-year-old first language (L1) Korean children and 41 foreign language (FL) learners who are Hong Kong Chinese college students. Korean children performed tasks of spelling, along with measures of syllable and phoneme coda awareness, phonological and orthographic working memory, morphological awareness, vocabulary, and orthographic knowledge. Among Korean 5-year-old children, coda awareness and orthographic working memory explained unique variance in spelling of phonologically consistent syllables, whereas syllable and coda awareness, orthographic working memory, orthographic knowledge, and vocabulary all explained unique variance in spelling of inconsistent syllables. When Chinese college students were tested on spelling of Korean Hangul as a foreign language, along with a battery of tasks in Korean similar to those administered to the L1 children, only orthographic working memory significantly explained spelling of consistent syllables, whereas only vocabulary knowledge explained spelling of inconsistent syllables. In both groups, spelling accuracy was lower in phonologically inconsistent than in consistent Hangul syllables. These findings suggest that different cognitive demands are involved in early spelling of phonologically consistent and inconsistent syllables in Korean Hangul among L1 and FL learners.