Introduction: Adverse childhood experiences (ACEs) constitute a signifcant global mental health burden. Prior studies typically investigated the impact of ACEs on mental health using a cumulative risk approach; most ACEs studies were also conducted in Western settings. Purpose: This study aimed to examine ACEs using a pattern-based approach and assess their associations with mental health outcomes by early adulthood in East Asia. Methods: The present study included measures of exposure to 13 categories of ACEs, depression, anxiety, maladjustment, and posttraumatic stress in a sample of 1346 university students from Hong Kong, China, Taiwan, and Japan. Results: Latent class analysis indicated three distinct patterns of ACE exposure: Class 1: Low ACEs (76.0%); Class 2: Household Violence (20.6%); and Class 3: Household Dysfunction (3.4%). Those representing Class 3 had signifcantly more ACEs compared with those in Classes 1 or 2. Controlling for age and sex, those in Class 2 reported signifcantly higher depression and maladjustment symptoms compared with those in Class 1; both Classes 2 and 3 had signifcantly higher anxiety symptoms and odds for meeting diagnostic criteria for posttraumatic stress disorders compared with those in Class 1. Conclusions: Study fndings suggest that young adults’ mental health, at least under certain contexts, is more closely linked with the nature and pattern of ACE co-occurrence, rather than the number of ACEs.