Mountain Equipment Co-op (now called 1077 Holdings Co-operative) was a Canadian co-op that started the MEC outdoor gear retail brand. The MEC brand name, assets and store leases were purchased by the American private investment firm Kingswood Capital Management's subsidiary Mountain Equipment Company in October 2020. 1077 Holdings Co-operative remains active to deal with the remaining claims by creditors and will be wound up at some point in the future.

Mountain Equipment Co-op was formed as a Canadian consumers' co-operative to sell outdoor recreation gear and clothing exclusively to its members. Mountain Equipment Co-op was notable for its commitment to environmental protection and other causes. As a co-op, Mountain Equipment Co-op sold only to customers who held a lifetime membership, which was technically a share of the co-op. MEC (as a co-operative) was Canada's largest supplier of outdoor equipment. Following its founding in Vancouver, British Columbia in 1971, MEC expanded across Canada and grew to operate stores in 20 cities. Once catering to mountaineers and climbers, MEC targeted a broader, more urban clientele, having added more clothing as well as cycling and yoga supplies. At its peak MEC had over 5.4 million members in Canada and internationally.

Facing mounting financial losses in 2019 and during the COVID-19 pandemic in Canada, in September 2020, without consulting its membership, the board of directors of the co-operative entered into an agreement to sell its assets to Kingswood. Following the completion of the deal in late October, Kingswood began operating the retail assets as a for-profit business.

MEC operated twenty-two retail stores and a "Corporate & Group Sales" store for large orders. Some MEC stores incorporated eco-friendly designs. The Ottawa and Winnipeg stores were the first and second retail buildings in Canada to comply with Canada's C2000 Green Building Standard, which acknowledges buildings that achieve energy consumption 50% less than similar conventional structures.

The organization designed and produced a significant proportion of its retail products and also carried other well-known brands. A significant proportion of the company's inventory was manufactured in Asia, with names and addresses of partner-factories made publicly available on the co-op's website. MECs' stated aim is to inspire and enable people to lead active, outdoor lifestyles. They accomplish this by selling outdoor gear, clothing and services. MEC's head office and telephone service centre were located in Vancouver. Its distribution centres were located in Brampton, Ontario and Surrey, British Columbia.

Chris Strashok, the author of an academic study, remarked in 2011 that "currently there are 3.3 million member owners making MEC the fourth largest democratic entity in Canada, after the governments of Canada, Ontario and Québec." Each year, every member of MEC has the opportunity to vote in the elections for its board of directors, as well as on "special resolutions", through a variety of methods. Before the election period, an information package with platforms of candidates and information on resolutions is distributed. Election results are announced at the annual general meeting.

MEC is governed by a nine-member board of directors. Each year, three directors are elected to three-year terms.

MEC holds its annual general meeting in Vancouver, BC. At this meeting, the Chief Executive Officer and Committee members deliver their annual reports, and answer questions from co-op members. "Other resolutions" may also be brought forward and voted upon. The AGM is typically webcast and members can log in and ask questions. Typically, members recite their member numbers before speaking and these numbers are recorded in the official meeting transcript.