This study reports on an analysis of accent and gender differences in the realisation of the fricative /s/ within three accents of English: London, Cambridge, Belfast. There were 30 speakers in the study. Using multilevel modelling, significant differences between accents in the dynamic acoustics of the alveolar fricative /s/ are evident. Significant gender differences in the fricative energy measure trajectories are also found, within each accent. We further discuss the implications of these differences to our understanding of the role of gender and accent in the realisation of spectra movements in English fricatives, highlighting the necessity of a dynamic approach to sociophonetic acoustic variation.