Ubisoft Divertissements Inc., doing business as Ubisoft Montreal, is a Canadian video game developer and a studio of Ubisoft based in Montreal.

The studio was founded in April 1997 as part of Ubisoft's growth into worldwide markets, with subsidies from the governments of Montreal, Quebec, and Canada to help create new multimedia jobs. The studio's initial products were low-profile children's games based on existing intellectual property. Ubisoft Montreal's break-out titles were 2002's Tom Clancy's Splinter Cell and 2003's Prince of Persia: The Sands of Time. Subsequently, the studio continued to develop sequels and related games in both series, and developing its own intellectual properties such as Assassin's Creed, Far Cry, Watch Dogs, and For Honor.

By October 2022, the studio employed over 4,000 staff, making it the largest in the world. The studio helped to establish Montreal as a creative city, and brought other video game developers and publishers to establish studios there.

Following Ubisoft's initial public offering in 1996, the Montreuil, France-based publisher began looking to expand into more global markets. Establishing a studio in Quebec was of strong interest to the company; according to Ubisoft Montreal's CEO Yannis Mallat, a Quebec studio would allow it to bring in French-speaking employees and help with communication with the Montreuil headquarters, and was in close proximity to the United States, one of the largest markets for video games.

At the same time, the city of Montreal in Quebec was looking to recover from job losses due to disappearing manufacturing and textile industries from the early 1990s. The controlling political party, Parti Québécois (PQ), pursued new job creation in technology, computers, and multimedia. Lobbyist Sylvain Vaugeois, hearing that Ubisoft was searching for jobs, came up with a plan called Plan Mercure which would incentivize Ubisoft to found a studio in Montreal by having the government subsidize each employee CA$25,000 for five years, but the government rejected this plan, believing it was too expensive for use of public funds. Vaugeois still went on to meet with Ubisoft, inviting it to visit Montreal and suggesting Plan Mercure was viable, and upon its visit, discovered that it had been misled, leading to some embarrassment on the city and province. PQ representatives of Quebec's and Montreal's government met with Ubisoft to convince it to establish a studio in Quebec after hearing that Ubisoft was considering a studio instead near Boston or in New Brunswick, and recognized they needed to follow on some form of Vaugeois' Plan Mercure to convince Ubisoft to form a studio in Montreal. Pierre Pettigrew, the Minister of Human Resources Development worked with the Quebec and federal government to come to a solution, whereby the two governments would split the previously considered CA$25,000 per employee (CA$15,000 from the Quebec government) to provide 500 new jobs to young persons and provide training in the multimedia sector. Ubisoft was agreeable to this, and established Ubisoft Montreal (formally named Ubisoft Divertissements Inc.) on 25 April 1997. The studio was founded in offices in the Peck Building, a former textile factory, located in the Mile End neighbourhood along Saint-Laurent Boulevard.

Martin Tremblay joined the studio as executive vice-president in 1999, and was promoted to chief operating officer a year later.

The studio began with 50 employees, with half having coming from Ubisoft's Montreuil headquarters, and the other hired in under the government subsidies. According to Mallet, a founding myth of the company was that they had thrown the new employees in a room with computers and were told to develop a game, but Mallet did acknowledge that there was a lack of experience in game development from this group. Initially, the studio developed children's games based on licensed intellectual property (IP) such as Donald Duck: Goin' Quackers and games based on the Playmobil series of toys. While these were not critically significant games, they sold well to keep the studio profitable, and allowed it to establish an internal program for creating its own IP.

Ubisoft Montreal's break-out title came through Tom Clancy's Splinter Cell, released in 2002. Prior to this, Ubisoft had closed down an internal development studio at the New York offices in 1999, which had been working on a game called The Drift, a third-person shooter with elements of stealth. Ubisoft had found the game lacking cohesion, and despite efforts to rebrand it as a potential James Bond game, Ubisoft opted to halt development and transfer key staff and all the work in progress to Ubisoft Montreal. The next year in 2000, Ubisoft acquired Red Storm Entertainment, which had successfully produced games based on Tom Clancy novels. The acquisition included the licence to develop more Tom Clancy-based games, as well as access to the Unreal game engine. The Ubisoft Montreal team started experimenting with modern spy gadgetry within the existing Drift elements, and found some potential promise to make a game in the Tom Clancy's series from it. With Metal Gear Solid 2: Sons of Liberty soon to be released, Ubisoft Montreal was tasked with creating the Metal Gear Solid killer, which resulted in the first Splinter Cell game. The Montreal studio continued to develop several of the Splinter Cell sequels through 2010.