["Applied Psychology: Health and Well-Being, Volume 18, Issue 3, June 2026. ", "\nAbstract\nAs social isolation becomes increasingly prevalent in the digital era, this research investigates the potential of AI‐facilitated co‐experiences to alleviate loneliness through two experiments with healthy Chinese adults. In Experiment 1 (N = 180), we examined beliefs about three imagined activities (co‐singing, co‐running, and co‐diagnosing) with human versus AI partners by assessing anticipated loneliness change, social presence, companionship, and empathy. Results supported the hypothesis of positive AI‐mediated co‐experience, albeit weaker than human, with co‐singing/co‐running anticipated to reduce loneliness more than co‐diagnosing. In Experiment 2 (N = 60), we tested actual co‐singing, manipulating partner type (human/AI) and mode (physical/virtual). Replicating core measures, co‐singing with an AI partner significantly reduced loneliness, supporting its efficacy. Notably, human co‐singing enhanced social presence and empathy more in physical than virtual mode, whereas AI's efficacy was unaffected by mode. These findings demonstrate the potential of AI‐facilitated co‐experiences as a loneliness intervention, with benefits robust across delivery contexts.\n"]