Background Osteoarthritis (OA) is a chronic, disabling, and prevalent disorder. As there is no cure for OA, long-term self-management is paramount. Support groups (SGs) can facilitate self-management among people living with OA. Understanding preferences in design and features of SGs, including online SGs (OSGs), among people with OA can inform future development of SG interventions for this condition. Objective The objective of this study was to investigate health care– and health information–seeking behavior, digital literacy, and preferences for the design of SGs in people with OA. The study also explored the perceived barriers and enablers to being involved in OSGs. Methods An online survey study was conducted with a mixed method design (quantitative and qualitative). Individuals aged ≥45 years with knee, hip, or back pain for ≥3 months were recruited from an extant patient database of the Institute of Bone and Joint Research via email invitations. Quantitative elements of the survey included questions about sociodemographic background; health care– and health information–seeking behavior; digital literacy; and previous participation in, and preferences for, SGs and OSGs. Respondents were classified into 2 groups (Yes-SG and No-SG) based on previous participation or interest in an SG. Group differences were assessed with Chi-square tests (significance level set at 5%). Responses to free-text questions relating to preferences regarding OSG engagement were analyzed qualitatively using an inductive thematic analysis. Results A total of 415 people with OA completed the survey (300/415, 72.3% females; 252/415, 61.0% lived in a major city). The Yes-SG group included 307 (307/415, 73.9%) participants. Between the Yes-SG and No-SG groups, there were no differences in sociodemographic characteristics, health care– and health information–seeking behavior, and digital literacy. An online format was preferred by 126/259 (48.7%) of the Yes-SG group. Trained peer facilitators were preferred, and trustworthiness of advice and information were highly prioritized by the respondents. Qualitative analysis for OSG participation revealed 5 main themes. Lack of time and motivation were the main barriers identified. The main enablers were related to accessibility, enjoyment of the experience, and the content of the discussed information. Conclusions These findings highlight the preferences in design features and content of SGs and OSGs and may assist in the further development of such groups.