Background: It is poorly understood how public perception of the difference between brain death and circulatory death may influence attitudes towards organ donation. We investigated the public opinion on brain death versus circulatory death and documented inconsistencies in the legislations of countries with different cultural and socioeconomic backgrounds. Methods: Using a crowdsourcing approach, we randomized 1072 participants from 30 countries to a case report of organ donation after brain death or to one following circulatory death. Further, we sampled guidelines from 24 countries and 5 continents. Results: Of all participants, 73% stated they would be willing to donate all organs, while 16% would want to donate some of their organs. To increase the rate of donations, 47% would agree with organ donation without family consent as the default. Exposure to “brain death” was not associated with a lesser likelihood of participants agreeing with organ donation (82.1%) compared to “circulatory death” (81.9%; relative risk 1.02, 95% CI 0.99 to 1.03; p = .11). However, participants exposed to “circulatory death” were more certain that the patient was truly dead (87.9% ± 19.7%) than participants exposed to “brain death” (84.1% ± 22.7%; Cohen's d 0.18; p = 0:004). Sampling of guidelines revealed large differences between countries regarding procedures required to confirm brain death and circulatory death, respectively. Conclusions: Implementation of organ donation after circulatory death is unlikely to negatively influence the willingness to donate organs, but legislation is still brain death-based in most countries. The time seems ripe to increase the rate of circulatory death-based organ donation.