As environmental challenges rise, digital nudging offers a promising strategy to promote sustainable decision-making. However, existing research often neglects different cultural backgrounds, limiting its applicability across global contexts. This study addresses the gap by investigating how Hofstede’s cultural dimensions influence the effectiveness of digital nudges. Employing a scenario-based online experiment, participants from Germany, Portugal, and the United States encountered either no nudge, a simplification nudge, or a social norm nudge. Our findings reveal that both digital nudges promote sustainable decision-making. Contrary to expectations, simplification nudges were less effective in high uncertainty avoidance cultures, suggesting a need for more comprehensive information. Furthermore, social norm nudges were more effective in collectivist cultures, aligning with their emphasis on social cohesion. Thus, we demonstrate the importance of culturally tailored nudging strategies, advancing the understanding of digital nudging’s role in cross-cultural decision-making and global sustainability efforts.