Yes, you are absolutely allowed to bring your own food on United Airlines in 2026. This is a savvy move, as United transitioned in March 2026 to a "Pre-order Only" model for fresh Economy meals on most domestic and short-haul international flights; if you didn't order via the app 24 hours in advance, your only onboard options are pre-packaged snack boxes. You can bring sandwiches, salads, or snacks through security, though any liquids or "spreadable" foods (like yogurt, hummus, or peanut butter) must comply with the 3-1-1 TSA rule (3.4 oz or less). Note that if you are flying internationally, you must consume or dispose of any fresh fruits, vegetables, or meat products before landing to comply with strict agricultural customs regulations at your destination.