American Airlines does not have a formal "dress code" for standard passengers, but they do enforce a "Conditions of Carriage" policy that allows them to deny boarding for inappropriate or offensive attire. To ensure a smooth flight in 2026, you should avoid clothing with profanity, explicit graphics, or drug references. You must wear shoes (no bare feet) for safety and hygiene, and extremely revealing clothing—such as sheer fabrics or tops that don't cover the torso—can lead to removal from the flight. For comfort, experts suggest breathable layers (like cotton or wool) to handle the fluctuating cabin temperatures and closed-toe shoes to protect your feet during boarding and in the event of an emergency. If you are traveling on a "buddy pass" or as an employee guest, you are held to a much stricter "Business Casual" standard, which requires collared shirts, long pants or skirts of appropriate length, and neat footwear. For regular travelers, "loungewear" or pajamas are generally acceptable as long as they provide adequate coverage and do not contain offensive messaging.