Background: Gene expression studies have shown that brain transcripts involved in myelin synthesis or maintenance are up regulated during sleep, indicating that poor sleep may impact upon white matter microstructure (Bellesi et al., 2013). In support of this hypothesis, diffusion tensor imaging (DTI) studies of primary insomnia have documented reduced fractional anisotropy (FA) within fronto-subcortical tracts (Li et al,. 2016; Spiegelhalder et al., 2013). Symptoms of poor sleep are not limited to clinical populations, though, and are reported to affect up to half of older adults. Here, we use DTI to examine the relationship between sleep quality and white matter in a UK community-dwelling, occupational-based cohort (Filippini et al., 2014). Methods: Sleep quality was measured using the Pittsburg Sleep Quality Inventory in 448 members of the Whitehall II cohort (90 females, age 69.2 ± 5.1 years). Analysis of DTI data was carried out using Tract Based Spatial Statistics, with voxelwise correlations between sleep quality and fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD) performed using Randomise. Age, gender and education level were included as covariates and the significance threshold set at p<0.05 using threshold-free cluster-enhancement. Results: 147 participants (33%) displayed PSQI scores greater than or equal to 6 and were classified as having poor sleep quality. Compared with participants classified as good sleepers, poor sleepers displayed significantly increased RD in widespread regions, including within fronto-subcortical tracts. Conclusions: Poor sleep quality was associated with reduced white matter integrity in community-dwelling older adults, in overlapping regions to those identified in studies of primary insomnia. Interventional studies will shed light on whether improving poor sleep can have beneficial effects on white matter microstructure during the ageing process.