Yes. In Settings > Delivery Zones, click the dropdown arrow on the Create zone button and choose Import KML, then drag in your .KML file. Zone names from the file apply automatically, and you can rename them or set a route colour before saving. Boundaries drawn in tools like Google Earth work well; KMZ or GeoJSON files should be converted to .KML first. Available in both EasyRoutes for Shopify and EasyRoutes for Web.
See: Delivery Zones