Public trust in science is pivotal, yet its measurement often lacks complexity. We developed, tested, and validated the theory-based multidimensional Public Trust in Science (PuTS) Scale. Data from two German online panel surveys (nW1 = 3,439; nW2 = 1,030) confirmed the superiority of five dimensions (expertise, integrity, benevolence, transparency, dialogue) over one, two, or four. We also introduced a concise five-item version (PuTS-5). External validation employed conspiracy beliefs and science populism. Our instrument, rooted in theory, provides an empirically manageable approach to assess public trust in science and may improve future research endeavors on the science–public trust relationship.