BACKGROUND: Physical inactivity represents a major health concern for older adults. Most social, at-home physical activity (PA) interventions use videoconference, email, or telephone communication for program delivery. However, evidence suggests that these platforms may hinder the social connection experienced by users. Recent advancements in virtual reality (VR) suggest that it may be a rich platform for social, at-home interventions because it offers legitimate options for intervention delivery and PA. OBJECTIVE: This pilot study aims to determine the feasibility and acceptability of VR compared to videoconference as a medium for remote group-mediated behavioral intervention for older adults. The information generated from this investigation will inform the use of VR as a medium for intervention delivery. METHODS: Nine low-active older adults (mean age 66.8, SD 4.8 y) were randomized to a 4-week home-based, group-mediated PA intervention delivered via VR or videoconference. Feasibility (ie, the total number of sessions attended and the number of VR accesses outside of scheduled meetings) and acceptability (ie, the number of participants reporting high levels of nausea, program evaluations using Likert-style prompts with responses ranging from -5=very difficult or disconnected to 5=very easy or connected, and participant feedback on immersion and social connection) are illustrated via descriptive statistics and quotes from open-ended responses. RESULTS: None of the participants experienced severe VR-related sickness before randomization, with a low average sickness rating of 1.6 (SD 1.6) out of 27 points. Attendance rates for group meetings were 98% (59/60) and 96% (46/48) for the VR and videoconference groups, respectively. Outside of scheduled meeting times, participants reported a median of 5.5 (IQR 5.3-5.8, range 0-27) VR accesses throughout the entire intervention. Program evaluations suggested that participants felt personally connected to their peers (VR group: median 3.0, IQR 2.5-3.5; videoconference group: median 3.0, IQR 2.7-3.3), found that goals were easy to accomplish (VR group: median 3.0, IQR 2.8-3.3; videoconference group: median 3.0, IQR 2.6-3.4), and had ease in finding PA options (VR group: median 4.0, IQR 3.5-4.3; videoconference group: median 2.0, IQR 1.6-2.4) and engaging in meaningful dialogue with peers (VR group: median 4.0, IQR 4.0-4.0; videoconference group: median 3.5, IQR 3.3-3.8). Open-ended responses regarding VR use indicated increased immersion experiences and intrinsic motivation for PA. CONCLUSIONS: These findings suggest that VR may be a useful medium for social PA programming in older adults, given it was found to be feasible and acceptable in this sample. Importantly, all participants indicated low levels of VR-related sickness before randomization, and both groups demonstrated very high attendance at meetings with their groups and behavioral coaches, which is promising for using VR and videoconference in future interventions. Modifications for future iterations of similar interventions are provided. Further work using larger samples and longer follow-up durations is needed. TRIAL REGISTRATION: ClinicalTrials.gov NCT04756245; https://www.clinicaltrials.gov/study/NCT04756245.