Resting-state functional magnetic resonance imaging (fMRI) provides a new window into the brain bases of mindfulness. In resting-state scans, participants lie in the scanner in a state of wakeful rest, and low-frequency fluctuations of the brain signals are measured. These brain fluctuations cohere into networks like the default mode network (DMN), the salience network (SN), and the central executive network (CEN), each with different functional roles and different topography. In this chapter, we summarize and synthesize the literature on resting-state functional connectivity (FC) and mindfulness. We provide a mechanistic model of how networks like the DMN, SN, and CEN interact to produce a state of mindfulness, and the role of mindfulness expertise. We review how resting-state FC may change with mindfulness interventions, and how trait mindfulness might relate to trait-like variation in resting-state FC. Broadly, the extant literature provides several network signatures of mindfulness, including reduced within-DMN connectivity, anticorrelations between the DMN and attentional networks, increased dynamic flexibility, and more. We additionally discuss discrepancies in the mindfulness FC literature and suggestions toward addressing them. Finally, we describe future directions including network-based fMRI neurofeedback during mindfulness skill acquisition.