Yes, you are absolutely permitted to bring hair spray on a cruise, as it is considered a standard personal toiletry. Unlike airlines, which have strict "3-1-1" liquid rules for carry-on bags, most cruise lines—including Royal Caribbean, Carnival, and Norwegian—allow you to bring full-sized aerosol cans of hair spray in both your carry-on and checked luggage. However, there are a few safety restrictions to keep in mind: the hair spray must be for personal use, and you should avoid bringing excessive quantities that could be flagged as a fire hazard. Crucially, while hair spray is allowed, other "heat-producing" items often used in hair styling, like clothing irons or steamers, are strictly prohibited due to fire risks. Hair straighteners and curling irons are generally allowed, provided they are in good working condition and not left unattended. If you are flying to your cruise port, remember that TSA rules will apply to your hair spray during the flight portion of your journey (3.4 oz limit for carry-on), but once you reach the ship, you can pack as much as you need for your vacation.