Solitude during adolescence is a potentially double edged sword. Involuntary (non-self-determined solitude) is associated with loneliness, which is known to predict many forms of psychological ill-being. In contrast, freely chosen (self-determined solitude) is associated with healthy developmental outcomes. It is possible that cultural attitudes towards solitude could influence the way adolescents think about and engage in solitude. The present study examined whether South African adolescents from individualist and collectivist cultures differ in their motivations for solitude, using the Motivation for Solitude Scale (MSS-SF). Respondents included 426 adolescents from collectivist and 266 from individualist cultures, between 14 and 18 years of age (mean age = 15.7). For valid cross-cultural comparisons, measurement equivalence was established using invariance and differential item functioning analysis. Results for the measurement invariance analysis (MI) marginally failed to support scalar invariance. Given criticism that MI is overly restrictive, Rasch analysis was used to test for uniform DIF, which supported invariance. Next, Bayesian analysis was used to investigate group differences. There was no difference between the cultural groups for non-self-determined solitude, but, adolescents from individualist cultures were less likely to engage in self-determined solitude. Results support the cross-cultural application of the MSS-SF, and point to a possible cultural bias against self-determined solitude in individualist cultures, despite its potential benefits.