The Kingston dyke complex forms a regionally developed belt of sheeted bimodal dykes within the Avalon composite terrane of southern New Brunswick, Canada. Dyke orientation relative to the belt suggests their injection accompanied sinistral movement, and the belt has previously been attributed to transform activity within the late Precambrian magmatic arc regime typical of the Avalon composite terrane in the Northern Appalachians. However, rhyolite dykes of the sheeted complex yield a U-Pb age of 435.5 ± 1.5 Ma that is interpreted to date their emplacement. The complex therefore provides evidence of Early Silurian sinistral displacement in the Northern Appalachians. Such movement is suggested by palaeomagnetic data and may record the accretion of the Avalon composite terrane to cratonic North America.