Purpose: To describe adolescent binge drinking trajectories across grades 8e11 and examine their associations with pubertal timing, socioeconomic status (SES), and structured activity and sport involvement. Methods: Longitudinal data were analyzed from the Youth Activity Participation Study (YAPS), an annual survey of youth in 39 schools across Western Australia (N ¼ 1,342). Results: Latent class growth analysis revealed four binge drinking trajectory groups: Accelerating (early onset, increased frequency), Steep Increase (delayed onset, rapid escalation), Slow Growth (delayed onset, gradual increase) and Stable Low (abstinence). Accelerating was characterized by early pubertal timing, low SES, and more sport involvement in grade 8, relative to Stable Low. The groups did not significantly differ in their grade 8 activity participation. However, for early maturers, greater grade 8 activity participation was associated with a decreased probability of belonging to Steep Increase relative to Stable Low. Conclusions: Early pubertal timing and sports participation increased the odds of belonging to a problematic binge drinking trajectory. For youth at-risk due to early pubertal timing, structured activities appear to be protective against a problematic developmental course of binge drinking