[1] HMCS Halifax was the first of an eventual twelve Canadian-designed and Canadian-built vessels which combine traditional anti-submarine capabilities with systems to deal with surface and air threats as well.

In November 2008, a Lockheed Martin Canada-led team including Saab AB, Elisra, IBM Canada, CAE Professional Services, L-3 Electronic Systems and xwave, was awarded the contract.

[7][8] To reflect the changing long-term strategy of the Navy during the 1980s and 1990s, the Halifax-class frigates was designed as a general purpose warship with particular focus on anti-submarine capabilities.

[11] As built the Halifax-class vessels deployed the CH-124 Sea King helicopter, which acted in concert with shipboard sensors to seek out and destroy submarines at long distances from the ships.

[9] As built, the anti-shipping role is supported by the RGM-84 Harpoon Block 1C surface-to-surface missile, mounted in two quadruple launch tubes at the main deck level between the funnel and the helicopter hangar.

[7][9] For anti-aircraft self-defence the ships are armed with the Sea Sparrow vertical launch surface-to-air missile in two Mk 48 Mod 0 eight-cell launchers placed to port and starboard of the funnel.

[9] A Raytheon/General Dynamics Phalanx Mark 15 Mod 21 Close-In Weapon System (CIWS) is mounted on top of the helicopter hangar for "last-ditch" defence against targets that evade the Sea Sparrow.

[a] The gun is capable of firing 2.4-kilogram (5.3 lb) shells at a rate of 220 rounds per minute at a range of more than 17 kilometres (11 mi).

[9] The Government of Canada announced on 5 July 2007 a $3.1 billion refit program for the Halifax class which would take place from 2010 to 2018 and extend the ships' service lives through to the 2030s.

[15] Faced with delays and restrictions from the International Traffic in Arms Regulations, the Navy opted to modernize the Halifax class using as much non-American equipment as possible,[further explanation needed] including technology from Canada, Sweden, Germany, Netherlands and Israel.

The International Traffic in Arms Regulations has also been blamed for the delay of the CH-148 Cyclone which was running two years behind the original schedule.

[17] The refit program was formally announced as completed on the west coast by Victoria Shipyards on 29 April 2016 by the Minister of National Defence Harjit Sajjan when Regina was returned to the Royal Canadian Navy.

[22] Although not part of the refit, Raytheon Canada Limited was awarded a contract of $180 million for eight years to overhaul, convert and repair all Canadian CIWS to a Block 1B Baseline 1 configuration.

[23] It was announced by the Department of National Defence that Hewitt Equipment was chosen to replace the diesel generators aboard the Halifax-class vessels in June 2015.

[26] As part of the refit, Thales Canada supplied the Sirius long-range Infrared Search and Track (IRST) for the Halifax class.

In 2015, Canada acquired twelve sets of X and S-Band navigation radars from Raytheon Anschütz for the class.

[33] Rheinmetall Waffe Munition GmbH received a contract to provide 14 Passive Electronic Countermeasures Systems (ECM).

[34] The Halifax class received two Navy Multi-band Terminals (NMT), installed on the forward port and starboard sides of the hangar, to increase its satellite communications capabilities.

This system was augmented by the Maritime Satellite Communications Upgrade (MSCU), featuring the AN/USC-69(V3) antenna installed on the hangar top.