Objective: Adverse childhood experiences (ACEs), which refer to childhood traumatic events, have been identified as risk factors for tobacco use in adulthood. However, studies are limited on the effect of sex on the association of ACEs with e-cigarettes and dual use of e-cigarettes and cigarettes. This study explored sex differences in the association of ACEs with e-cigarettes, cigarettes, and dual use of e-cigarettes and cigarettes among adults in the United States. Methods: This was a cross-sectional analysis of data from adults aged [greater than or equal to]18 years in the 2020 Behavioral Risk Factor Surveillance System (N = 62,768). ACEs, the independent variable, was a composite score assessed from 11 questions (with responses yes-1 or no/never-0) related to childhood emotional abuse, physical abuse, sexual abuse, and household dysfunction and categorized as 0 (reference), 1, 2, 3, or [greater than or equal to] 4. The dependent variable, tobacco use patterns, included nonuse (reference), e-cigarette only, cigarette only, and dual use of e-cigarettes and cigarettes. Multinomial logistic regression was performed to test the interaction between sex and ACEs while controlling for potential confounders. Results: Although we found no statistically significant interaction by sex, a greater number of ACEs were associated with higher odds of the different tobacco use patterns among females and males, with varying strengths of associations. Specifically, females who reported [greater than or equal to] 4 ACEs compared with none had higher odds of e-cigarette (aOR [95% CI]: 3.58 [1.49-8.63]), cigarette (2.57 [1.72-3.83]) and dual use (3.25 [1.79-5.91]) relative to nonuse. Males with [greater than or equal to] 4 ACEs had higher odds of cigarette (1.75 [1.15-2.65]) and dual use (7.64 [3.95-14.79]). Conclusion: Our findings underscore the importance of developing appropriate, tailored trauma-informed intervention strategies for females and males. It is also important to consider ACEs in designing tobacco-specific preventive programs to curb initiation and promote cessation among U.S. adults.