List of mergers and acquisitions by Microsoft

Microsoft's first acquisition was Dynamical Systems Research (DSR) on June 20, 1986. DSR developed a clone of IBM's TopView operating environment for DOS; Microsoft employed their technology and programmers to further the development of Windows. Its second acquisition was Forethought on July 30, 1987. Forethought was founded in 1983 and developed a presentation program that would later be known as Microsoft PowerPoint.

On December 31, 1997, Microsoft acquired Hotmail.com for $500 million (~$905 million in 2024), its largest acquisition at the time, and integrated Hotmail into its MSN group of services. Hotmail, a free webmail service founded in 1996 by Jack Smith and Sabeer Bhatia, had more than 8.5 million subscribers earlier that month.

In 1999, Microsoft reportedly discussed a buyout of Nintendo. However, execs failed to negotiate a deal, with Xbox co-inventor Kevin Bachus explaining "They just laughed their asses off."

Microsoft acquired Seattle-based Visio Corporation on January 7, 2000, for $1.375 billion (~$2.37 billion in 2024). Visio, a software company, was founded in 1990 as Axon Corporation, and had its initial public offering in November 1995. The company developed the diagramming application software, Visio, which was integrated into Microsoft's product line as Microsoft Visio after its acquisition.

On July 12, 2002, Microsoft purchased Navision for $1.33 billion (~$2.21 billion in 2024). The company, which developed the technology for the Microsoft Dynamics NAV enterprise resource planning software, was integrated into Microsoft as a new division named Microsoft Business Solutions, later renamed to Microsoft Dynamics.

Microsoft purchased aQuantive, an advertising company, on August 13, 2007, for $6.333 billion (~$9.2 billion in 2024). Before the acquisition, aQuantive was ranked 14th in terms of revenue among advertising agencies worldwide. aQuantive had three subsidiaries at the time of the acquisition: Avenue A/Razorfish, one of the world's largest digital agencies, Atlas Solutions, and DRIVE Performance Solutions.

Microsoft acquired the Norwegian enterprise search company Fast Search & Transfer on April 25, 2008, for $1.191 billion (~$1.7 billion in 2024) to boost its search technology.

On May 10, 2011, Microsoft announced its acquisition of Skype Technologies, creator of the VoIP service Skype, for $8.5 billion (~$11.7 billion in 2024). With a value 32 times larger than Skype's operating profits, the deal was Microsoft's largest acquisition at the time. Skype would become a division within Microsoft, with Skype's former CEO Tony Bates, then the division's first president, reporting to the CEO of Microsoft.

On September 2, 2013, Microsoft announced its intent to acquire the mobile hardware division of Nokia (which had established a long-term partnership with Microsoft to produce smartphones built off its Windows Phone platform) in a deal worth 3.79 billion euros, along with another 1.65 billion to license Nokia's portfolio of patents. Steve Ballmer considered the purchase to be a "bold step into the future" for both companies, primarily as a result of its recent collaborations. The acquisition, scheduled to close in early 2014 pending regulatory approval, did not include the Here mapping service or the infrastructure division Nokia Solutions and Networks, which will be retained by Nokia. While the deal went through, in May 2016 Microsoft abandoned its mobile business and sold the Nokia feature phone line.

In September 2014, Microsoft purchased Mojang for $2.5 billion (~3.4 billion in June 2025).

On June 13, 2016, Microsoft announced it planned to acquire the professional networking site LinkedIn for $26.2 billion, to be completed by the end of 2016. The acquisition would keep LinkedIn as a distinct brand and retain its current CEO, Jeff Weiner, who will subsequently report to Microsoft CEO Satya Nadella. The acquisition was completed on December 8, 2016.

On June 4, 2018, Microsoft acquired the popular code repository site GitHub for $7.5 billion (~$9.2 billion in 2024) in Microsoft stock.

On September 21, 2020, Microsoft announced its intent to acquire ZeniMax Media and all its subsidiaries for $7.5 billion (~$8.93 billion in 2024). The acquisition was completed on March 9, 2021.

On January 18, 2022, Microsoft acquired Activision Blizzard, an American video game holding company, for $68.7 billion in cash. The deal was finalized on October 13, 2023, with the total cost of the acquisition amounting to $75.4 billion, following international government regulatory review of the action.