BACKGROUND: Parental characteristics that influence child physical activity (PA) behavior often co-occur. An analytic approach that considers these co-occurring patterns can help researchers better understand the overall context of parental influence. The study aims were to: (1) identify diverse patterns of the relationships among parental characteristics, (2) examine the influence of these parental patterns on child sport participation and moderate-to vigorous-intensity PA (MVPA) trajectories during childhood and adolescence, and (3) examine whether family support mediates the influence of the parental patterns on child sport participation and MVPA trajectories. METHODS: We used data from 408 Iowa Bone Development Study cohort families (97 % Caucasians; 65 % mothers with a 4-year college degree). From ages 5 to 19 years, the cohort participated in seven accelerometry assessments, reported sports participation every 6 months, and reported perceived family support for PA at age 15. Parents reported family income, education level, and regular PA participation in high school and adulthood. Structural equation modeling was conducted to identify the latent classes represented among these parental characteristics. Sex-adjusted multivariable logistic regression analyses were conducted to predict sports participation trajectories and MVPA trajectories by latent class and family support. RESULTS: Three parent latent classes were identified: higher family socioeconomic status (SES) and regular PA in both high school and adulthood by both the father and mother (Group 1); lower family SES and regular PA in high school by the father (Group 2); and lower family SES and no regular PA in high school by the father (Group 3). Sex-adjusted ORs of the "drop-out from sports participation" pattern for the children in Groups 1 and 2, compared to Group 3, were 0.38 (95 % CI = 0.20, 0.72) and 0.51 (95 % CI = 0.26, 1.00), respectively. Sex-adjusted ORs of the "decreasing from moderate MVPA" pattern for the children in Groups 1 and 2, compared to Group 3, were 0.29 (95 % CI = 0.11, 0.75) and 1.16 (95 % CI = 0.40, 3.37), respectively. Adding family support to the logistic regression model only slightly changed the ORs. CONCLUSIONS: The findings from this study suggest that among lower SES families, the father's role may be important to promote youth to sustain sports participation.