The use of social networking sites is associated with objectification tendencies of the self and others. However, only few studies investigate how users actually perceive sexualizing content on Instagram. In a recent study, we showed that perceiving sexy Instagram posts as appropriate and less revealing goes along with self-sexualization in German participants and that Instagram users tend to be more sexist than non-users. The present study aimed to replicate these findings in a cross-nations study to test for cultural differences. We asked N = 2055 persons from six different countries (Germany, Spain, United States, Italy, Turkey, and South Africa) to rate sexy Instagram posts with respect to revealing clothing, appropriateness, and attractiveness and collected self-report data on sexism, enjoyment of sexualization, and Instagram usage behavior. Our results show associations between the perception of the presented posts as appropriate, sexism, and self-sexualizing tendencies in all countries. Strength of the associations are mainly the same across all countries. Participants from Spain, the U.S., and Italy reported the lowest sexism scores and the most liberal ratings for the presented photos. We find no substantial main effect of mere Instagram use on sexism or photo ratings. The results suggest that Instagram use does not necessarily alter the perception of sexualized stimuli, but that greater appreciation of self-sexualizing others goes along with self-sexualization. This effect seems to be culturally invariant. The found mean differences between countries are plausible, but future studies should aim to obtain representative samples to allow serious assumptions about cultural effects.