Fortis Inc. is a St. John's, Newfoundland and Labrador based international diversified electric utility holding company. It operates in Canada, the United States, Central America, and the Caribbean. In 2015, it earned $6.7 billion CAD.

Fortis was formed in 1987 when shareholders of the regulated transmission and distribution utility Newfoundland Light & Power Co. voted to form a separate holding company. NL&P shares were exchanged for Fortis shares on a one-to-one basis, with the regulated NL&P becoming a 100% owned subsidiary.

Fortis currently owns the following regulated utilities:

Fortis also operates three non-regulated companies:

The company expanded into Western Canada in 2003 with its purchase of Aquila, Inc.'s Canadian assets, formerly owned by TransAlta, Canada's largest publicly traded utility. As a result of this acquisition, Fortis became one of Alberta's major regulated electrical distribution companies, serving 415,000 Albertans in 2005. ATCO Electric is Alberta's other regulated distribution company. Also as a result of the 2003 acquisition, Fortis owns regulated generation, transmission, and distribution assets in British Columbia.

In 2007, Fortis acquired Terasen Gas from Kinder Morgan, which had sold the BC gas utility as a non-strategic asset included in its 2005 acquisition of Terasen Inc.

In addition to its regulated Canadian assets, Fortis also owns unregulated assets in Ontario, British Columbia, and Newfoundland. The majority of its unregulated business consists of hydroelectric generating plants.

Fortis' interests in the Caribbean include a 67% interest in Belize Electricity Limited (BEL) and a 95% interest in Belize Electric Co. Ltd. The Belize Association of Non-Government Organisations took Fortis to the Judicial Committee of the Privy Council in 2003 to have a new environmental assessment of the Chalillo Dam on the Macal River which was a hydroelectricity development project. Ecologists were concerned over the future of species such as the scarlet macaw, the tapir and the black howler monkey as the project would flood 10 km of rainforest in Belize. Celebrities such as Harrison Ford and Cameron Diaz supported a movement to stop this dam. Fortis and the Government of Belize supported the project.

On May 30, 2011, it was announced that Fortis has plans to acquire Central Vermont Public Service, an electric utility in the US state of Vermont, for US$700 million, pending stockholder and regulatory approval; this acquisition would be Fortis' first utility acquisition in the United States. Gaz Métro offered a higher price and acquired CVPS.

On February 21, 2012, CH Energy Group (a holding company for Central Hudson Gas & Electric, an upstate New York utility), announced a pending acquisition by Fortis valued at $1.5 billion. On June 27, 2013, Fortis Inc. closed on its acquisition of CHG.

In 2013, Fortis announced its acquisition of UNS Energy, an Arizona utility company.

On February 9, 2016, Fortis announced an agreement to acquire ITC Holdings Corp., the largest independent transmission utility in the United States, for US$11.3 billion in cash and stock.