Can a Cosmetologist Inject Botox?

The answer to both questions is yes. Is it legal? Is it wise? Those are different questions.
If a cosmetologist were the only person around and a woman needed help with her delivery, then the cosmetologist could deliver the baby. Delivering babies and injecting Botox are medical procedures.
I am being interviewed by Spike TV this weekend; they are producing a show on "Botox deaths". There have been a handful of severe Botox side effects related to the unscrupulous injection of "imitation Botox" that was labeled for experimental use only. There have been no reported cases of the use of legitimate Botox for cosmetic use causing any deaths.
I agree with Dr. Julius Few, a very well respected plastic surgeon and member of the Injectables safety board whose answer to this question is excellent. This is a medical procedure that should be performed under medical supervision.
Dr. P

The laws are unclear and vary between state to state.  However, Botox is a very effective but potent medication.  It should only be injected by experienced board-certified plastic surgeons and dermatologists.  Would you go to the hair salon to have your gall bladder removed?  Not likely.  Good luck.

Because Botox is a prescription medication, it can only be injected by a physician or a medical practitioner working directly under the supervision of a physician. In California, a nurse, Physician's assistant and/or nurse practitioner's can all provide Botox injections working under the supervision of a physician. Cosmetologists are excluded in California.
We assume that they are in other states as well, and would caution you because if the person is using fake Botox and has no malpractice insurance (which they would not if they are not a physician's office) then your options might be limited in the event anything goes wrong.