A 7 year old can wear deodorant although you should make sure it's safe and formulate for kids.
A good first deodorant for kids is Kopari Aluminum Free Coconut Deodorant.
Kopari Aluminum Free Coconut Deodorant is a great kids deodorant which is gentle going on and easy to apply and includes sage oil and coconut oil without any phthalates, parabens or aluminum.
Dove solid stick deodorant is also a good deodorant for kids.
While Dove solid stick deodorant is not solely for kids or preteens, the aluminum, alcohol, and baking soda-free formula helps reduce skin irritation without sacrificing odor protection which makes it great for kids.
There's no specific age for a child to start wearing deodorant or antiperspirant.
Many start using deodorant in their teens.
Some kids start using deodorant as soon as puberty starts to cause body odor, which can be as early 8 or 9 years old for some children.
Then again, some people never use any deodorant, even as adults.
Deodorant is safe for your kids to use when they're ready.
In fact, many brands make a deodorant that is specially formulated for younger deodorant wearers.
Deodorant helps with the odor coming from the armpits while antiperspirant helps minimize sweat.
Decide with your child what will work best (there are some combo options, as well).
Both deodorant and antiperspirant come in a variety of fragrances.
Let your child choose what they prefer, for a little extra buy in.