Stop Tobacco Sales to Youth Act of 2015

Amends the Jenkins Act to include within the definition of "cigarette" electronic cigarettes, cigars, and pipe tobacco.

Defines "electronic cigarette" to mean any electronic device that delivers nicotine, flavor, or other substance via an aerosolized solution (including an electronic cigarette, cigar, pipe, or hookah) to the user inhaling from the device, excluding any product that: (1) is approved by the Food and Drug Administration for sale as a tobacco cessation product or for another therapeutic purpose, and (2) is marketed and sold solely for such a therapeutic purpose.

Makes specified exceptions with respect to Indian tribes and tribal matters.