Objectives <p>Mindfulness has been described as the ability to be aware in the present moment with an attitude of non-judgment. Network theory offers a novel framework to understand which symptoms are core (i.e., central) to mindfulness. Additionally, network theory and analysis provide an alternative way to conceptualize how mindfulness may be a protective factor against psychopathology. The primary aim of this paper was to provide a systematic review of empirical research that has used network analysis to study mindfulness.</p> Method <p>Studies were included if they were empirical, incorporated a measure of mindfulness, and used a network analytic approach. We identified 21 manuscripts.</p> Results <p>Core processes in mindfulness networks include describing one’s beliefs, thoughts, and emotions in words and accepting one’s emotions. In addition, core facets in mindfulness networks are describing and acting with awareness. Several protective factors were also identified as core to mindfulness networks, including self-compassion, well-being, and interoceptive awareness. Mindfulness appears to bridge to psychopathology through rumination, acceptance of emotions, non-judging, non-reacting, and acting with awareness. There also appear to be several notable changes in mindfulness networks after mindfulness-based interventions.</p> Conclusions <p>Future research should examine whether targeting core mindfulness processes may improve mindfulness-based interventions. Mindfulness-based interventions for anxiety, depression, and eating disorders may be particularly effective.</p> Preregistration <p>This study was not preregistered.</p>