Daubert v. Merrell Dow Pharmaceutical Inc., 509 U.S. 579 (1993) is a well-known and often cited opinion issued from the United States Supreme Court concerning the rules and factors applicable to admitting expert scientific evidence in federal trial courts in the United States.

This case is important in the series of expert evidence decisions related to the two-step admissibility analysis to clarify at what stage each of these issues might best be considered by the trial judge.