Children's environmental health (CEH) has a 25-year history at the US Environmental Protection Agency (EPA), during which the agency has advanced CEH through research, policy, and programs that address children's special vulnerability to environmental harm. However, the Trump administration took many actions that weakened efforts to improve CEH. The actions included downgrading or ignoring CEH concerns in decision-making, defunding research, sidelining the Children's Health Protection Advisory Committee, and rescinding regulations that were written in part to protect children. To improve CEH, federal environmental statutes should be reviewed to ensure they are sufficiently protective. The administrator should ensure the EPA's children's health agenda encompasses the most important current challenges and that there is accountability for improvement. Guidance documents should be reviewed and updated to be protective of CEH and the federal lead strategy refocused on primary prevention. The Office of Children's Health Protection's historically low funding and staffing should be remedied. Finally, the EPA should update CEH data systems, reinvigorate the role of the Children's Health Protection Advisory Committee, and restore funding for CEH research that is aligned with environmental justice and regulatory decision-making needs. (Am J Public Health. 2022;112(1):124-134. https://doi.org/10.2105/AJPH.2021.306537).