Among 88,183 U.S. high school students, marijuana use declined from 23.1% in 2011 to 15.8% in 2021, with first-time use before age 13 dropping from 8.1% to 4.9%. In 2021, use was highest among 12th graders (22.4%) and 11th graders (18.7%). Notably, girls (17.8%) surpassed boys (13.6%) in reported use in 2021, reversing past trends. While Asian, Hispanic, and white adolescents saw declines, Black adolescents had a higher usage rate of 20.5% in 2021, indicating ongoing racial disparities.