In Sri Lanka, the military of Sri Lanka is responsible for external defense, maritime security, and maintaining internal security; it has sent small numbers of personnel on UN peacekeeping missions; from 1983 to 2009, the military fought against the Liberation Tigers of Tamil Eelam (LTTE), a conflict that involved both guerrilla and conventional warfare, as well as acts of terrorism and human rights abuses, and cost the military nearly 30,000 killed; since the end of the war, a large portion of the Army reportedly remains deployed in the majority Tamil-populated northern and eastern provinces; the military over the past decade also has increased its role in a range of commercial sectors including agriculture, hotels, leisure, and restaurants

Sri Lanka traditionally has had close security ties to India; the Sri Lankan and Indian militaries conduct exercises together, and India trains approximately 1,000 Sri Lankan soldiers per year; in recent years, Sri Lanka has increased military ties with China, including acquiring military equipment, hosting naval port calls, and sending personnel to China for training (2025)