To circumvent the challenges of longitudinal human studies, rodents can be leveraged as they have experimentally tractable lifespans. At present, only limited number of studies have tracked longitudinal resting-state functional connectivity in rodents, with these studies only using male animals. The aim of this study is to determine sex-specific developmental trajectories of brain development using functional connectivity analysis. Male and female Wistar rats were scanned at postnatal day 28, 35, 49, 70 and 91 under light sedation. Functional connectivity was measured between several regions of interest, including the hippocampus, prefrontal cortex, striatum, thalamus and hypothalamus. A linear mixed effects models was used to analyse the effects of age and sex on functional connectivity. Preliminary analyses revealed connection-specific effects of age, sex- and sex-by-age interactions. Overall, sex differences were observed for hippocampus-hypothalamus connectivity, and for prefrontal cortex-striatum connectivity, while an age by sex interaction was observed for the connectivity between the striatum and thalamus. These preliminary results suggest baseline differences in functional connectivity between male and female rats, some of which may be modulated by age. Further analyses with a larger sample, including normative development modelling will be reported.