The Pacific class (also known as the Pacific Forum class and the ASI 315 class) is a class of 22 patrol boats built by Australia and donated to twelve South Pacific countries. The vessels were constructed between 1985 and 1997 and are operated by the militaries, coast guards or police forces of the twelve island nations. These boats are supported by the Pacific Patrol Boat Program and used primarily for maritime surveillance and fisheries protection.

The United Nations Convention on the Law of the Sea took effect in 1982. It introduced a 200-nautical-mile (370 km; 230 mi) exclusive economic zone (EEZ) to the territories of all nations with an ocean coastline. Several Southwest Pacific island nations found themselves responsible for policing an area of ocean that was beyond their maritime capability, and often significantly larger than their land territories (at its most extreme, the EEZ of Tuvalu dwarfs its landmass by a ratio of almost 1:28,000). Following requests by several Pacific nations for assistance from the governments of Australia and New Zealand, the Australian government created a Defence Cooperation Project named the Pacific Patrol Boat Program to design and provide suitable patrol boats to nearby island nations. The program also provided training and infrastructure to support these ships. The Program was officially announced by Australian Prime Minister Bob Hawke during the South Pacific Forum meeting held in Canberra on 29 and 30 August 1983.

Requests for tenders were issued in August 1984. Australian Shipbuilding Industries (ASI) designed a small vessel capable of maritime surveillance and interdiction, search and rescue operations, and fisheries protection. A smaller prototype was constructed by ASI in 1984. The prototype was later sold to the Royal Solomon Islands Police Force and named Savo. The contract for the Pacific class was awarded to ASI on 9 May 1985 and construction began in September 1985. Initially ten ships were planned to be produced for eight countries, with the first ship, HMPNGS Tarangau, delivered to the Papua New Guinea Defence Force on 16 May 1987. The program continued until 15 ships were ordered, then was terminated before being reopened in February 1993. By the time the program concluded, 22 ships had been delivered to 12 countries, with the final ship, FSS Independence, delivered to the Federated States of Micronesia in June 1997. The Pacific Patrol Boat Project is the largest and most complex defence co-operation project ever funded by Australia.

Each patrol boat has a length of 31.5 metres (103 ft 4 in), a beam of 8.1 metres (26 ft 7 in), a draught of 1.8 metres (5 ft 11 in), and a full load displacement of 162 tonnes. They are fitted with two Caterpillar 3516TA diesel engines, which provide 2,820 horsepower (2,100 kW) to two propeller shafts, driving the vessel at a maximum of 20 knots (37 km/h; 23 mph). Pacific-class vessels have a maximum range of 2,500 nautical miles (4,600 km; 2,900 mi) at 12 knots (22 km/h; 14 mph), and can remain at sea for up to ten days. Armament varies depending on the operating nation; the patrol boats may carry GAM-BO1 20 mm guns, 7.62 mm machine guns, or 12.7 mm machine guns, and these need not be permanently fitted. Each ship carries a Furuno 1011 surface search radar, which operates in the I band. The ship's company varies between 14 and 18, depending on the operating nation. In order to reduce construction and maintenance costs, the vessels were built to commercial, as opposed to military, standards. This facilitates companies in the operating nations to be capable of providing parts and minor maintenance in mind.

There were initial problems with the propellers, engine cooling systems, and air conditioning, but these were fixed before the completion of the third ship of the class. The class underwent refits during each ship's seventh or eighth year of operation, and again at the fifteenth year (which was ongoing until 2012). This has extended the predicted service life of the class to 2027.

Several variant designs for the Pacific class have been produced by Australian Shipbuilding Industries (later Transfield ASI, then Tenix), for a variety of operators.

Four patrol boats of a slightly shortened 31-metre (102 ft) design were produced for the Kuwait Coast Guard. An unarmed version of this design is also marketed to the operators of oil platforms as a crew transport.

Six modified versions of the Pacific class were built for the Hong Kong Marine Police as the Protector class. The main difference is the installation of a pump-jet engine to supplement the main propulsion.