Online sexual activities (OSA) refer to Internet-based activities, behaviours, and materials that are sexual in nature. Many young adults engage in OSA, but report doing so infrequently. Most OSA outcome research has focused on negative effects of only some types of OSA (e.g., viewing pornography online). The goal of this study was to enhance knowledge on the range of OSA outcomes by qualitatively exploring young adults' self-reported negative and positive outcomes from OSA experiences generally. University/College students from Canada (n = 246), Germany (n = 411), Sweden (n = 299), and the USA (n = 123) completed an online survey that included open-ended questions about "one of the most positive/negative effects that engaging in online sexual activities has had on your life". More participants provided positive outcome responses than negative outcome responses. Qualitative analysis of the responses suggested a wide range of positive and negative outcome content that fit into seven bi-polar, higher-order themes: No Outcomes, Relationship Outcomes, Sexual Experience, Emotional Outcomes, Knowledge, Personal Outcomes, and Security. We found no variations in themes or their respective codes across the four countries. The findings suggests that researchers, educators, health care and psychology providers need to include multiple dimensions of positive and negative, personal and interpersonal, sexual and non-sexual OSA outcomes in their work.