You can take deodorant spray on a plane, but there are specific rules you must follow.

Carry-on Rules for Deodorant Spray

• Deodorant sprays are considered aerosols and are subject to the TSA 3-1-1 liquid rule for carry-on bags.
• The spray container must be 3.4 ounces (100 milliliters) or less.
• It must fit inside a single quart-sized, clear, zip-top plastic bag with your other liquids and aerosols.
• The aerosol container must have a cap to prevent accidental release.

Checked Luggage Rules

• You can carry larger deodorant spray cans in checked baggage.
• The total quantity of aerosols in checked baggage must not exceed 70 ounces (2 kilograms), and no single container should exceed 18 ounces (500 milliliters).
• Aerosol cans must be protected against accidental activation.

Additional Advice

• Avoid spraying deodorant spray inside the airplane to prevent triggering smoke alarms.
• Stick deodorants do not have these restrictions and can be freely carried.

So yes, you can take deodorant spray on a plane if you pack it according to these guidelines.