In this article, we critically discuss different versions of the fairness objection to the legalisation of neuro-doping. According to this objection, legalising neuro-doping will result in some enjoying an unfair advantage over others. Basically, we assess four versions. These focus on: 1) the unequal opportunities of winning for athletes who use neuro-doping and for those who do not; 2) the unfair advantages specifically for wealthy athletes; 3) the unfairness of athletic advantages not derived from athletes’ own training (conventionally understood); and 4) the unfair health care costs imposed on everyone as a result of athletes’ use of neuro-doping. We conclude that none of these versions offer a convincing principled fairness-based objection to legalising neuro-doping.