Objective: The infant temperament behavioral inhibition is a potent risk factor for development of an anxiety disorder. It is difficult to predict risk for behavioral inhibition at birth, however, and the neural underpinnings are poorly understood. The authors hypothesized that neonatal functional connectivity of the ventral attention network is related to behavioral inhibition at age 2 years beyond sociodemographic and familial factors. This hypothesis is supported by the ventral attention network's role in attention to novelty, a key feature of behavioral inhibition. Method: Using a longitudinal design (N=45), the authors measured functional connectivity using MRI in neonates and behavioral inhibition at age 2 using the Infant-Toddler Social and Emotional Assessment. Whole-brain connectivity maps werecomputedfor regions from the ventral attention, default mode, and salience networks. Regression analyses related the semaps to behavioral inhibition at age 2, covarying for sex, social risk, and motion during scanning. Results: Decreased neonatal functional connectivity of three connections was associated with increased behavioral inhibition at age 2. One connection (between the right ventrolateral prefrontal cortex and the right temporalparietal junction) included the ventral attention network seed, and two connections (between the medial prefrontal cortex and both the right superior parietal lobule and the left lateral occipital cortex) included the default mode network seed. Conclusions: Neonatal functional connectivity of the ventral attention and default mode networks is associated with behavioral inhibition at age 2. These results inform the developmental neurobiology of behavioral inhibition and anxiety disorders and may aid in early risk assessment and intervention.