Quebecor (written without an accent on the first e, even in French) is a Quebec-based company with two main spheres of activity:

• Quebecor World is the largest commercial printing company in the world, with 39 000 employees around the world.

• Quebecor Média which owns and operates:
  • Vidéotron (cable TV)
  • Sun Media corporation (newspapers)
  • TVA (television network)
  • Netgraphe (Internet websites including Canoe.ca portal and Archambault.ca)
  • Archambault stores (books, music and video)
  • Book publishing companies
  • The number-one magazine publishing company in Quebec
  • Vidéotron Télécom (telecommunications)
  • Le SuperClub Vidéotron (DVD and VHS movie rental stores)

Quebecor was founded and remains run by the Péladeau family.

Quebecor Média's wide range of media properties enables it to execute "convergence" strategies that are sometimes criticized. When the TVA television network was running the program Star Académie (sort of a French-language "American Idol"-type program), it was heavily cross-promoted: TVA would mention it in the "entertainment" segment of news broadcasts, the newspaper Le Journal de Montréal would run several pages on it, magazines would run articles on it, and so forth. The show was even hosted by company CEO Pierre-Karl Péladeau's girlfriend, TV personality Julie Snyder. The strategy worked: the show's first season was a huge ratings success and a cultural phenomenon, and continues in future seasons.

On August 20, 2004, Quebecor announced that two of its subsidiaries, TVA and Sun Media, would apply to the CRTC to purchase Toronto One, a television station in Toronto, Ontario.