This study investigated the unique contribution of orthographic awareness, letter knowledge, and patterning skills to early literacy and arithmetic competence. A total of 145 third-year kindergarten (K3) children (M[subscript age]: 73.43 months, SD = 5.36; 70 boys, 48%) from Hong Kong participated in this study. Children were assessed on their patterning skills, orthographic awareness, letter knowledge, verbal short-term working memory, visual-spatial perception, Chinese word reading, word writing, and arithmetic competence. With demographic variables and cognitive skills controlled, multilevel regression models indicated that patterning skills uniquely contributed to Chinese word reading and arithmetic competence but not to Chinese word writing. Orthographic awareness was a strong predictor of the three academic outcomes. Letter knowledge was significantly predictive of word reading and word writing but not of arithmetic competence. These findings highlight the differential roles of orthographic awareness, letter knowledge, and patterning skills in children's literacy and arithmetic skills.