The Pakistan Marines (Urdu: سمندری پاکستان or بحریہَ پاکستان) or simply as Pak Marines, is an expeditionary and amphibious warfare uniform service branch within the Pakistan Navy, consisting of the naval officers and other personnel to perform their duties within the Marines. Pakistan Marines are responsible for providing force protection in littorals, using the mobility of the Pakistan Navy to provide creeks defence, ground based air defence and Force protection.

In the Pakistani military leadership structure, the Marines are the expeditionary and amphibious branch within the Navy, often working closely with the Pakistan Army for training, executing expeditionary operations and logistics purposes.

Initially established and commissioned on 1 June 1971 in East-Pakistan, to assist Pakistan Army in riverine warfare. GHQ employed this infant force in successfully evacuating Pakistan Army units from encirclement by Indian Army. They were headquartered in PNS Bakhtiar and PNS Titumir to oversee the tactical riverine /waterborne operations. This small but valiant force soon started to make significant impact on retrograde waterborne operations of Pakistan and saved many lives. Post war scenario led to their decommissioning in 1974 due to no riverine area of operations left with Pakistan that time.

On 25 November 1990, the Marines were re-organized and recommissioned under Cdr. Obaidullah–since then they have been a component of the Navy, conducting expeditionary operations with the special forces of army and the navy. The Marines are primarily tasked with quick response and marine reconnaissance objectives to guard the coastal and amphibious regions of the country, and receives training at the School of Infantry and Tactics by the Pakistan Army's instructors.

In 2010, Marines, in close co-ordination with the Pakistan Army, Navy, and Air Force, were working around the clock to rescue villagers trapped by the country's worst deluge in 80 years.

The Pakistan Marines traces their history back to East Pakistan when the infantry battalion, dedicated towards the amphibious operations with the Pakistan Army, was commissioned in the Navy on 1 June 1971. Initially, the Marines were modeled based on the British Royal Marines and were aimed towards conducting independent expeditionary and amphibious operations in a geographical region that was essentially a dead-level plain, which made it difficult for the Pakistan Army to conduct mechanized operations, though an ideal theatre for amphibious ground forces.

The Marines were initially tasked to counter the Indian Army in Chittagong and Khulna with only four patrol boat and improvised imported amphibious vehicles. Due to lack of training and vessels, misunderstanding of the amphibious terrains, operational capabilities, the Marines failed to produce any significant results to counter the insurgency that resulted in their decommissioning in 1974.

Nonetheless, the Marines continued to exists in its rudimentary form until 1988 to meet the fundamental security requirements of Pakistan Navy offshore establishments in the country. Following the introduction of the Mistral weapon system in the Navy, the Marines were re-commissioned under Cdr. Obaidulla (PN. Service number 1558) with Manora Fort at the vicinity of the PNS Qasim serving its first forward base on 14 April 1990.