α-band-mediated brain network communication underlies visual processing and is disrupted in visual deficits. We aimed to develop and evaluate an EEG-based neurofeedback targeting α-band connectivity of source-reconstructed visual areas with the rest of the brain, to determine whether modulating this network enhances detection of low-contrast visual stimuli. In this randomized, active-controlled study, 28 participants received real-time auditory neurofeedback designed to increase global α-band connectivity between target regions and the rest of the brain. Feedback targeted interactions with the visual cortex (V1-V3) in the active group and with the frontal cortex in the control group. Each participant completed two neurofeedback sessions on separate days. Resting-state connectivity, visual, and attentional performance were assessed on the days preceding and following training. 50% of participants in the active group successfully increased α-band connectivity of the targeted visual cortex, whereas connectivity decreased in the control and non-responder groups. Improvements in stimulus detection were observed primarily in male participants and appeared to be influenced by additional factors, including baseline performance levels. Even brief network-based neurofeedback interventions can enhance α-band connectivity of visual areas.