Fort Hammenhiel (Tamil: அம்மன்னீல் கோட்டை, romanized: Am'maṉṉīl Kōṭṭai; Sinhala: හැමන්හිල් බලකොටුව, romanized: Hæminanhil Balakotuwa) is a fort built around a small island between the islands of Kayts and Karaitivu of Jaffna Peninsula in Northern Sri Lanka.

[1][2] The Dutch, under the command of Captains Cornelies Reb, Piester Waset and N. van der Reede, captured the fort in March 1658 and subsequently renamed it Hammenhiel (Heel of the Ham), as they considered that shape of Ceylon resembled a smoked ham and the fort was located at the point where the shank bone projects.

[6] The British used the fort firstly as a maximum security prison and then as an infectious diseases hospital.

During the Second World War, on orders from Admiral Lord Mountbatten, Camp Hammenhiel was established in late 1944 to start a “Special Operations Group" under the command of Colonel Humphry Tollemache.

[1][7] In 1971 Rohana Wijeweera, founder leader of the Janatha Vimukthi Peramuna, was detained in the fort after his arrest.