AimThis pilot examined the effect of online peer support on mental health problems among individuals with post‐acute sequelae of COVID‐2019 (PASC).MethodsA single‐arm pre‐post design of online peer‐support design consisting of eight sessions of 1 h per week with three to six participants and two facilitators per group was performed. Participants were recruited from online communities, social media, and medical clinics for the PASC between May and August 2023. The degrees of depression, anxiety, loneliness, social withdrawal, and self‐esteem were measured pre‐ and post‐intervention. Participants' statements during the sessions were analyzed using thematic analyses.ResultsOf the 18 participants, three dropped out of the interventions, and 17 (including two participants who dropped out) completed the pre‐ and post‐intervention questionnaires. Depression severity significantly decreased in the paired t‐test and linear mixed model. The following interactions were extracted: conveying the same feelings, dealing with difficulties, showing empathy, enhancing the atmosphere, and adapting to suit health conditions. Impressions extracted from participating in the interventions included feelings of emotional support, a sense of bonding, changes in perspective, changes in behaviors or new actions through participation, inadequacy during sessions, and adverse effects associated with participation.ConclusionOnline peer support may be helpful in treating depression in individuals with PASC.