Yes, you are generally allowed to take deodorant on a plane. When traveling by air, the Transportation Security Administration (TSA) permits passengers to bring deodorant, in both solid and liquid forms, in their carry-on baggage. However, it is important to adhere to the liquid restrictions set by the TSA, which require all liquids to be in containers no larger than 3.4 ounces (100 milliliters) and placed in a clear, quart-sized plastic bag. It is recommended to familiarize yourself with the specific guidelines outlined by the TSA to ensure a smooth and hassle-free experience at airport security checkpoints.