Harry DeWolf-class offshore patrol vessel

Harry DeWolf-class offshore patrol vessels are warships of the Royal Canadian Navy (RCN) built within the Government of Canada Arctic and Offshore Patrol Ship (AOPS) procurement project, part of the National Shipbuilding Strategy. In July 2007 the federal government announced plans for acquiring six to eight icebreaking warships for the RCN.

The vessels are modelled on the Norwegian Coast Guard NoCGV Svalbard and as of 2007 were projected to cost CA$3.5 billion to construct with a total project procurement budgeted to cost $4.3 billion in order to cover maintenance over the 25-year lifespan of the vessels. In 2018 it was reported that the cost of the first six ships had increased by $810 million over previous projections. In 2023 it was reported that the cost for the first six ships had increased by a further $780 million and that of the two envisaged vessels for the Coast Guard by an additional $100 million.

The lead ship of the class was announced as Harry DeWolf in September 2014, and four additional ships were named in 2015. Construction of the ships Harry DeWolf and Margaret Brooke started at the Halifax Shipyards in September 2015 and September 2016, respectively. Harry DeWolf and Margaret Brooke were originally planned to be delivered in 2019 and 2020 respectively. Harry DeWolf was officially launched on 15 September 2018. Margaret Brooke was launched on 10 November 2019. Max Bernays began construction in December 2017 and William Hall was also planned to begin in 2017, although construction was delayed to early 2019. Max Bernays was launched in October 2021, and was followed by William Hall in 2022. Frédérick Rolette was scheduled to begin construction in 2019, with construction on Robert Hampton Gray expected to begin in 2021. They were originally planned to be completed by 2022 and 2023, respectively. However, in 2020 it was confirmed that ships five and six (Frédérick Rolette and Robert Hampton Gray) would not begin construction until 2021 and 2022 respectively.

On 22 May 2019, an official announcement was made to begin the process of building two vessels for the Canadian Coast Guard, bringing the total number of ships in the class to eight.

In 2006 Prime Minister Stephen Harper had spoken about building three to four icebreakers capable of travelling through thick ice in the Arctic Ocean. In 2007 it was announced that the Canadian Armed Forces would purchase six to eight patrol ships having an ice class of Polar Class 5, meaning that they were capable of limited icebreaking, based on the Norwegian Svalbard class. This announcement was met with some controversy, and the proposed ships have been called "slush-breakers", by Dr. Gary Stern, a scientist aboard CCGS Amundsen, and Jack Layton of the NDP. However, it was notable that in 2005 of the nineteen Canadian Coast Guard icebreakers then in service, only six had an ice class higher than Polar Class 5.

In 2010 the Arctic and Offshore Patrol Ship Project was grouped with several other federal government ship procurement projects for the Royal Canadian Navy and Canadian Coast Guard into the National Shipbuilding Procurement Strategy (NSPS). The NSPS announced on 19 October 2011 that Irving Shipbuilding would be awarded the $25 billion contract to build six to eight Arctic patrol ships as well as fifteen other warships for the RCN over the next two decades.

In September 2014, Prime Minister Stephen Harper announced that the name of the first ship in the class would be Harry DeWolf, named in honour of wartime Canadian naval hero Harry DeWolf, and that the class would be named the Harry DeWolf class. In December it was found that not enough money had been projected to cover the cost of building the six to eight planned ships and that the budget would need to be increased, delaying the signing of the contract. However, in an effort to drive down costs, Irving Shipbuilding could only project building five ships with the option to build a sixth only if it came under budget. The budget for the project was increased from $3.1 billion to $3.5 billion to ensure a cash buffer. However, by 2018 that approach had been abandoned and the budget for the first six ships had reportedly increased to $4.3 billion.

On 13 April 2015 the government announced a second ship would be named Margaret Brooke in honour of Sub-Lieutenant Margaret Brooke, a Royal Canadian Navy Nursing Sister decorated for heroism for her efforts to save a fellow nursing sister after the sinking of the ferry SS Caribou during World War II. The third ship will be named Max Bernays for Chief Petty Officer Max Bernays who served aboard HMCS Assiniboine during the Second World War and was decorated for his actions during the sinking of the German submarine U-210. The fourth ship will be named for William Hall, a Victoria Cross (VC) recipient from Nova Scotia and the first black person to be awarded the VC, for his actions during the Siege of Lucknow. The fifth ship will be named for Frédérick Rolette, a French-Canadian sailor of Canada's Provincial Marine under the Royal Navy who, during the War of 1812, was second-in-command of the ship Lady Prevost at the Battle of Lake Erie, and led the capture of the American supply vessel Cayahoga Packet, in July 1812, an action instrumental in contributing to the capture of Detroit one month later.