In the American justice system, the jury is the ultimate and exclusive finder of fact. In particular, credibility determinations are sacrosanct, and no witness is permitted to “invade the province of the jury” by testifying as to another party’s credibility. This rule is strictly enforced despite being thoroughly discredited by behavioral research on the ability of jurors to detect deception. In the modern multilingual courtroom, this rule places linguistic minorities at a distinct disadvantage. The communication gap between cultures is vast, and courtroom interpretation suffers from many well-documented inadequacies that can profoundly affect a fact-finder’s conclusions about a non-English speaker’s credibility. In other circumstances, when it is reliable and will assist the trier of fact, courts routinely admit expert testimony. This Note advocates for a similar solution: where non-English speaking parties or witnesses would otherwise suffer prejudice, courts should abandon the “province of the jury” rule and allow expert testimony regarding a witness’ credibility.