Stop Theft of Intellectual Property Act of 2021 This bill makes the misappropriation of trade secrets a ground for deporting or barring an alien from entry into the United States. Specifically, an alien may be denied entry into the United States if there are reasonable grounds to believe that the alien has violated, is violating, or is seeking entry to violate any U.S. law relating to the misappropriation of trade secrets or economic espionage. Similarly, an alien may be deported if the alien has violated, is violating, or after admission into the United States violates any U.S. law relating to the misappropriation of trade secrets or economic espionage.