Abstract: A connector socket for external serial ATA (eSATA) and universal serial bud (USB) plugs has a casing, an eSATA contact set and a USB contact set. The casing has a cavity defined in the casing, an inner rear surface and a contact seat formed on and extending forward from the inner rear surface. The eSATA contact set is mounted on the contact seat and has multiple eSATA contacts being conductive and mounted on the contact seat. The USB contact set is mounted on the contact seat opposite to the eSATA contact set and has multiple USB contacts being conductive and mounted on the contact seat. The connector socket having the single contact seat is compact.