The Pakistan Army (Urdu: پاکستان فوج, romanized: Pākistān Fãuj, pronounced [ˈpaːkɪstaːn faːɔːdʒ]), commonly known as the Pak Army (Urdu: پاک فوج, romanized: Pāk Fãuj) is the land service branch and the largest component of the Pakistan Armed Forces. The President of Pakistan is the Supreme Commander of the Army. The Chief of Army Staff (COAS), a four-star general commands the army. The Army was established in August 1947 after Pakistan gained independence from the United Kingdom.^: 1–2 According to statistics provided by the International Institute for Strategic Studies (IISS) in 2021, the Pakistan Army has approximately 560,000 active duty personnel, supported by the Army Reserve, the National Guard and the Civil Armed Forces. Pakistani citizens can enlist for voluntary military service upon reaching 16 years of age, but cannot be deployed for combat until the age of 18 in accordance with the Constitution of Pakistan.

The primary objective and constitutional mission of the Pakistan Army is to ensure the national security and national unity of Pakistan by defending it against any form of external aggression or the threat of war. It can also be requisitioned by the Pakistani federal government to respond to internal threats within its borders. During events of national and international calamities and emergencies, it conducts humanitarian rescue operations at home and is an active participant in peacekeeping missions mandated by the United Nations (UN)—most notably playing a major role in rescuing trapped American soldiers who had requested for a quick reaction force during Operation Gothic Serpent in Somalia. Troops from the Pakistan Army also had a relatively strong presence as part of a larger UN and NATO coalition during the Bosnian War and larger Yugoslav Wars.^: 70

The Pakistan Army, a major component of the Pakistani military alongside the Pakistan Navy and Pakistan Air Force, is a volunteer force that has seen extensive combat during three major wars with India, several border skirmishes with Afghanistan at the Durand Line as well as a long-running insurgency in the Balochistan region which it has been combatting alongside Iranian security forces since 1948.^: 31 Since the 1960s, elements of the army have been repeatedly deployed to act in an advisory capacity in the Arab states during the events of the Arab–Israeli wars as well as to aid the United States-led coalition against Iraq during the First Gulf War. Other notable military operations during the global war on terrorism in the 21st century included: Zarb-e-Azb, Black Thunderstorm, and Rah-e-Nijat.

In violation of its constitutional mandate, it has repeatedly overthrown elected civilian governments, overreaching its protected constitutional mandate to "act in the aid of civilian federal governments when called upon to do so". The army has been involved in enforcing martial law against the federal government with the claim of restoring law and order in the country by dismissing the legislative branch and parliament on multiple occasions in past decades—while maintaining a wider commercial, foreign and political interest in the country. This has led it facing allegations of acting as a state within a state.

The Pakistan Army has a regimental system but is operationally and geographically divided into command zones, with its most basic fields being its various corps. The Pakistani constitution mandates the role of the president of Pakistan as the civilian commander-in-chief of the Pakistani military. The Pakistan Army is commanded by the Chief of Army Staff, who is by statute a four-star ranking general and a senior member of the Joint Chiefs of Staff Committee appointed by the prime minister and subsequently affirmed by the president. As of December 2022, the current Chief of Army Staff is General Asim Munir, who was appointed to the position on 29 November 2022.