Fredericton serves on MARLANT missions protecting Canada's sovereignty in the Atlantic Ocean and enforcing Canadian laws in its territorial sea and Exclusive Economic Zone.

Fredericton has also been deployed on missions throughout the Atlantic and to the Indian Ocean; specifically the Persian Gulf and Arabian Sea on anti-terrorism operations.

[5][6] To reflect the changing long term strategy of the Navy during the 1980s and 1990s, the Halifax-class frigate was designed as a general purpose warship with particular focus on anti-submarine capabilities.

[7] 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.

[7] 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.

[5][7] 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.

[7] 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.

Further improvements, such as modifying the vessel to accommodate the new Sikorsky CH-148 Cyclone helicopter and satellite links will be done separately from the main Frigate Equipment Life Extension (FELEX) program.

The existing 57 mm Mk 2 guns were upgraded to the Mk 3 standard and the Harpoon missiles were improved to Block II levels, the Phalanx was upgraded to Block 1B and the obsolete Sea Sparrow system was replaced by the Evolved Sea Sparrow Missile.

[11] On 5 April, while transiting the Gulf of Aden, the frigate responded to a distress call from the yacht Longo Barda which was under attack by pirates.

[10] Fredericton was among the Canadian warships that participated in Operation Sharp Guard, enforcing the United Nations blockade of Yugoslavia.

The fire was suppressed within a few minutes and the ship made a brief stop at the home base of Halifax before being given the all-clear to return to sea.

[16] On 6 October 2011, Fredericton was turned over to Irving Shipbuilding's Halifax Shipyards, to start the vessel's FELEX mid-life upgrading and modernization.

[19] The frigate joined Standing NATO Maritime Group 2 (SNMG2) in the Black Sea in March 2015 for training exercises.

[28] In April it was announced that Fredericton would be one of the test ships for the Royal Canadian Navy's planned reduced crew size trials.

[31] In September 2016 Fredericton was among the Canadian warships deployed to the NATO naval training exercise "Cutlass Fury" off the east coast of North America.

However, no cases were found aboard the ship and the vessel was ordered to cancel a number of other port calls while continuing its mission.

[36] The helicopter had been returning from a NATO training mission, with six members of the Canadian Armed Forces on board, at the time of the incident.

[40][41] The specialised salvage ship EDT Hercules was dispatched with Canadian and American military recovery teams from Souda Bay, Greece to recover the wreckage of the Cyclone helicopter on 25 May.

[46][47] Participating in the Norwegian led exercise FLOTEX 2021, on 18 November Fredericton reported a fire in the forward engine room.

[51] In January 2023, Fredericton departed Halifax for another six-month deployment in support of NATO operations in the Mediterranean Sea.