Onex Corporation is a Canadian investment management firm founded by Gerry Schwartz in 1984.

[2] In June 2007, General Motors sold Allison Transmission to financial investors Carlyle Group and Onex Corporation.

The company was sold off in 2019 to merge with AEG Facilities to form ASM Global.

[4] In 2019, Onex acquired Gluskin Sheff, a Toronto-based wealth management firm.

[5][6] In May 2020, Onex blamed a first-quarter net loss of $1.1 billion US dollars on the COVID-19 pandemic.