The last several years have featured the development of legal longtermism–the set of theories associated with the view that law should be concerned with ensuring the long-term future goes well. Although recent literature has shown that the principles underlying legal longtermism are widely endorsed across the anglosphere, it remains an open question whether these principles are endorsed across cultures. Here we surveyed laypeople (n=2,938) from 10 countries–Australia, Canada, Chile, Japan, Mexico, Spain, South Africa, South Korea, United Kingdom and United States–regarding law’s role in protecting future generations. We find participants in our sample widely endorse (a) increasing legal protection for future humans beyond current levels; (b) extending personhood and standing to some subset of humans living in the near and far future; and (c) prioritizing the interests of future people over those of present people in some national and international lawmaking scenarios. Taken together, these results suggest the notion of granting rights and legal protection to future generations is endorsed cross-culturally, carrying wide-ranging implications for legal theory, doctrine, and policy.