Background: Sugar-sweetened beverage consumption (SSB) among children is a main risk factor for childhood obesity and subsequent onset of chronic diseases including type 2 diabetes and cardiovascular disease. Introducing a tax on SSBs could potentially curb SSB consumption. However, empirical evidence remains limited and mixed. This study aims to assess the effect of an SSB tax on consumption among youth. Methods: Design Quasi-natural experiment and difference-in-difference (DID) analytical framework of pre- and post-tax SSB consumption among youth. Setting Philadelphia, PA; Seattle, WA; Oakland, CA; and Chicago Cook County, IL where sweetened beverage taxes were implemented, and other thirty cities without an SSB tax as controls. Participants 9th to 12th high school students Exposures Sweetened beverage excise taxes Main outcome and measures Effect of an SSB tax on the probability and quantity of soda, milk, and 100% fruit juice consumption. Results: Our DID estimation suggested that the introduction of an SSB tax was associated with a significant decline in soda consumption among high-school students in terms of probability (2.3 percentage points, CI, - 3.5 to -0.1, p<0.01) and quantity (0.48 of a can, equivalent to 5.76 ounces CI, -0.60 to -0.37, p < 0.01) of consumption. The decreased soda consumption was compensated by an increase in weekly milk consumption (0.55 glasses/ 4.4 ounces, CI, -0.44 to -0.66, p<0.01), whereas the consumption of 100% juice remained unchanged. The tax effects were more pronounced among normal weight, female, and racially Black/African American or White high school students compared to their counterparts. Conclusions: SSB taxes are an efficacious fiscal policy tool to curb SSB consumption among US youth.