It is well known that people conform to normative information about other people’s current attitudes and behaviors. Do they also conform to dynamic norms—information about how other people’s behavior is changing over time? We investigated this question in three online and two field experiments. Experiments 1 through 4 examined high levels of meat consumption, a normative and salient behavior that is decreasing in the United States. Dynamic norms motivated change despite prevailing static norms, increasing interest in eating less meat (Experiments 1–3) and doubling meatless orders at a café (Experiment 4). Mediators included the anticipation of less meat eating in the future (preconformity) and the inference that reducing meat consumption mattered to other people (Experiments 2 and 3). In Experiment 5, we took advantage of a natural comparison to provide evidence that dynamic norms can also strengthen social-norm interventions when the static norm is positive; a positive dynamic norm resulted in reduced laundry loads and water use over 3 weeks during a drought.