Is it safe for a child to take Tylenol and Benadryl together?

It depends on the age of the child. Tylenol (Acteaminophen) + Benedryl (Diphenhydramine) is the same thing as Tylenol PM. Tylenol is not recommended to be used on children under the age of 12. Consult with your child's primary care physician before giving them adult strength Tylenol.