This study aimed to test the effects of a standardized front-of-package (FOP) disclosure statement (indicating added sugar, non-nutritive sweetener (NNS) and juice content) on accuracy in assessing ingredients and perceived healthfulness of children’s drinks. In two randomized controlled experiments, the same participants (six hundred and forty-eight U.S. caregivers of young children ages 1-5 years) viewed drink packages and indicated if products contained added sugar or NNS and percent juice and rated drink healthfulness. Experiment 1 (E1) included novel (non-US) children’s drinks with a) product claims only (control), b) claims and disclosure, or c) disclosure only. Experiment 2 (E2) included existing children’s drinks (with claims) with a) no disclosure (control) or b) disclosure. Both experiments evaluated sweetened (fruit drink and flavored water) and unsweetened (100 % juice and juice/water blend) drinks. Potential individual differences (education level and race/ethnicity) in effects were explored. FOP disclosures significantly increased accuracy for most ingredients and drink types, including identifying the presence or absence of NNS in sweetened drinks, no added sugar in juice/water blends, and actual percent juice in fruit drinks and juice/water blends in both experiments. Disclosures also increased recognition that the novel 100 % juice and juice/water blend did not contain NNS or added sugar (E1) and existing sweetened drinks contained added sugar (E2). Disclosures reduced the perceived healthfulness of sweetened drinks but did not increase unsweetened drink healthfulness ratings. This study suggests that FOP disclosures on children’s drink packages can increase caregivers’ understanding of product ingredients and aid in selecting healthier children’s drinks.