Queenborough is a small town on the Isle of Sheppey in the Swale borough of Kent in South East England.

Queenborough is two miles (3.2 km) south of Sheerness. It grew as a port near the Thames Estuary at the westward entrance toThe Swale where it joins the River Medway. It is in the Sittingbourne and Sheppey parliamentary constituency.

Queenborough Harbour offers moorings between the Thames and Medway. It is possible to land at Queenborough on any tide and there are boat builders and chandlers in the marina. Admiral Lord Nelson, is reputed to have learned many of his seafaring skills in these waters, and also shared a house near the small harbour with his mistress, Lady Hamilton.

Queenborough today still reflects something of its original 18th-century seafaring history, from which period most of its more prominent buildings survive. The church is the sole surviving feature from the medieval period. The town was first represented by two members of parliament in 1572.