Purpose: Irritability is common in children and a symptom of multiple psychological disorders (e.g., depression, bipolar, anxiety). Despite these detrimental outcomes, to date, no study has examined developmental changes in neural patterns of irritability longitudinally. Our aims are thus to: (1) characterize concurrent neural correlates of irritability, (2) identify neural predictors in preschool age of subsequent school-age irritability, and (3) relate change in brain function to irritability in preschool-age and school-age. Participants: The sample (n=166 at wave 1, n=71 at wave 2, and n=65 at wave 3) is between the ages of 4 and 8, with varying levels of irritability. Data were collected at three time points, with a subset of participants followed up for visits one and two years later. Methodology: The present study utilized resting state functional connectivity MRI, which measures intrinsic connectivity in the brain when not doing any task (i.e., “at rest”). Whole-brain connectivity ANCOVA analyses were completed at the group level through Analysis of Functional NeuroImages’s 3dMVM program. Seed regions include left and right amygdala, and left and right ventral striatum connectivity. Parent-reported irritability was measured through a composite of selected questions (“stubborn, sullen, or irritable,” “sudden changes in mood or feelings,” “temper tantrums or hot temper”) from the Child Behavioral Checklist (CBCL). Results: At wave 1, higher levels of irritability were associated with greater concurrent amygdala connectivity with precuneus and cingulate gyrus (Aim 1). At wave 2, higher levels of irritability were associated with decreased concurrent ventral striatum connectivity with inferior parietal lobule (Aim 1). Additionally, ventral striatum connectivity with inferior occipital gyrus at preschool age predicted increased subsequent irritability at school age (Aim 2). Finally, irritability at preschool-age predicted changes across the preschool- to school-age period in ventral striatum and amygdala connectivity with multiple parietal regions (Aim 3). Discussion: Understanding the neural processes that contribute to childhood irritability can inform pathophysiological models of pediatric irritability and the development of targeted mechanistic interventions.