2018 Annual Report ONEX AND ITS OPERATING BUSINESSES Onex is a public company whose shares trade on the Toronto Stock Exchange under the symbol ONEX. Onex’ businesses have assets of $51 billion, generate annual revenues of $32 billion and employ approximately 217,000 people worldwide. Onex operates from offices located in Toronto, New York, New Jersey and London. ONEX ONCAP ONEX ONEX DIRECT PARTNERS CREDIT REAL ESTATE Onex Partners includes investments made through Onex Partners I, II, III, IV and V. ONCAP includes investments made through ONCAP II, III and IV. Throughout this report, all amounts are in U.S. dollars unless otherwise indicated. Table of Contents 9 Management’s Discussion and Analysis 91 Consolidated Financial Statements 87 Glossary 184 Shareholder Information CHAIRMAN’S LETTER Dear Shareholders, As a year comes to a close, we often look back with pride at our accomplishments on your behalf. This was not the case last year. Several of our operating businesses underperformed relative to our expectations, which con- tributed to a 6% annual decline in the fair market value of our private equity portfolio. It is no surprise our share price reflected the disappointment of our fellow shareholders and declined more steeply than the comparative indices. This is not the first time we have been disappointed in our performance, but thankfully it has been many years since we have had a year like this one. As anyone on our team will tell you, we are improving the performance of all our businesses and driving change where needed. As investors with controlling interests, this is exactly what we can and must do. We believe our efforts will be rewarded and have evidenced that confidence by repurchasing 1.2 million Subordinate Voting Shares at an average cost per share of $67.11 (C$86.78). The year was not without significant achievements: • We invested approximately $2.3 billion in nine new businesses, including: – Onex Partners’ investment in PowerSchool, a non-instructional software provider primarily to K-12 primary schools. PowerSchool is our first significant investment in the software sector; – Onex Partners’ acquisition of KidsFoundation, a leading provider of childcare services in the Netherlands. KidsFoundation is our first investment in a business headquartered in the Netherlands; and – ONCAP’s four investments totalling more than $310 million, with the largest investment through Walter Surface Technologies, a provider of innovative solutions for the metal working industry. • We returned approximately $1.9 billion to Onex and our partners, through realizations and distributions, including the sales of Mavis Discount Tire and Tecta America, as well as the initial public offering of SIG Combibloc; • We increased our assets under management at Onex Credit by 7% and now manage $10.3 billion. Con- tributing to the increase was the issuance of CLO-15 and the capital raised for our first private debt fund, of which more than 70% of the $1.1 billion of available capital has been invested; • We started investing Onex Partners V, a $7.15 billion fund, which further enhances Onex’ operating leverage on its private equity manager. Our total run-rate management fees from our private equity and credit platforms increased to $192 million; and • Our operating businesses completed 38 follow-on acquisitions, collectively raised or refinanced debt totalling $7 billion and paid down approximately $295 million of debt. Last year, our team invested $135 million across our private equity platform, credit funds and Onex shares, bringing our total investment to approximately $1.7 billion. Alignment between managers and shareholders is core to our culture and critical to our success. From all of us at Onex, we thank you for your continued support and look forward to sharing better news in the years to come. [signed] Gerald W. Schwartz Chairman and Chief Executive Officer, Onex Corporation Onex Corporation December 31, 2018 1 ONEX CORPORATION Who We Are and What We Do Onex is an investor first and foremost, with $6.4 billion of shareholder capital primarily invested in or commit- ted to private equity and non-investment grade credit. We also manage $23.2 billion of invested and committed capital on behalf of fund investors from around the world, including public and private pension plans, sovereign wealth funds, banks, insurance companies and family offices, that have chosen to invest alongside us. With an experienced management team, significant financial resources and no debt at the parent com- pany, Onex is well-positioned to continue building shareholder value through its investing and asset manage- ment activities. Private Equity Investing Founded in 1984, Onex is one of the oldest and most successful private equity firms. We acquire and build high- quality businesses in partnership with talented management teams. Onex invests through its two private equity platforms: Onex Partners for larger transactions and ONCAP for middle-market transactions. We are focused on three primary investment strategies: (i) cost reduction and operational restructurings; (ii) platforms for add-on acquisitions; and (iii) carve-outs of subsidiaries and mission-critical supply divisions from multinational corporations. We have built over 100 operating businesses, completing about 630 acquisitions with a total value of $78 billion. Onex’ private equity investing has generated a gross MOC of 2.6 times since inception, resulting in a 28% Gross IRR on realized, substantially realized and publicly traded investments. Credit Investing Established in 2007, our credit platform invests primarily in non-investment grade debt through its collateral- ized loan obligations, private debt and other credit strategies. We practise value-oriented investing, employing a bottom-up, fundamental and structural analysis of the underlying borrowers. We seek to generate strong risk- adjusted and absolute returns across market cycles. With a disciplined approach to investing and a focus on capi- tal preservation, Onex Credit now manages $10.3 billion. 2 Onex Corporation December 31, 2018 Onex Capital At December 31, 2018, Onex’ $6.4 billion of capital was primarily invested in or committed to its private equity and credit platforms. Onex’ $6.4 billion of Capital at December 31, 2018 Onex’ $6.8 billion of Capital at December 31, 2017 Large-Cap Private Equity 52% Large-Cap Private Equity 49% Cash and Near-Cash Items 23% Cash and Near-Cash Items 29% Middle-Market Private Equity 8% Middle-Market Private Equity 9% Credit 11% Credit 10% Real Estate and Other Investments 6% Real Estate and Other Investments 3% The How We Are Invested schedule details Onex’ $6.4 billion of capital at December 31, 2018 (December 31, 2017 – $6.8 billion). In the year ended December 31, 2018, Onex capital per share decreased by 5% (3% increase in Canadian dollars). Over the past five years, Onex capital per share has increased by 4% per year (9% per year in Canadian dollars). Onex Corporation December 31, 2018 3 OnexNav per Capital Shar pere (USD) Share (USD) (December 31, 2013 to December 31, 2018) $65 65 $60 60 $55 55 $50 4% 50 annual growth $45 over the past five years 45 $40 40 $35 35 Dec-2013 Dec-2014 Dec-2015 Dec-2016 Dec-2017 Dec-2018 30 Fund Investor Capital Onex manages $23.2 billion of invested and committed capital on behalf of investors from around the world. In November 2018, Onex completed fundraising for Onex Credit Lending Partners I, reaching aggregate com- mitments of $413 million, including Onex’ commitment of $100 million. Onex’ $23.2 billion of Fund Investor Capital Onex’ $24.2 billion of Fund Investor Capital at December 31, 2018 at December 31, 2017 Onex Partners 55% Onex Partners 57% Onex Credit 40% Onex Credit 36% ONCAP 7% ONCAP 5% Fund investor capital includes capital managed on behalf of co-investors and the Onex management team. 4 Onex Corporation December 31, 2018 Asset Management Onex’ management of fund investor capital provides two significant financial benefits: (i) a committed stream of annual management fees and (ii) the opportunity to share in fund investors’ profits. Onex has run-rate manage- ment fees of $192 million, consisting of $142 million from private equity and $50 million from credit. During the 12 months ended December 31, 2018, combined management fees and carried interest received more than offset operating expenses. For the 12 months ended December 31, 2018, fee-generating capital under management decreased by 5% to $20.6 billion, driven by realizations in private equity, the redemption of CLO-2 and net fair value decreases in Onex’ private equity portfolio. Partially offsetting these decreases was the closing of CLO-15 and Onex Credit Lending Partners. Over the past five years, fee-generating capital under management has increased by 11% per year. FFee-Generatingee-Generating Capital Under Management (December 31, 2013 to December 31, 2018) 22 22 20 20 18 18 16 16 14 Billions 11% 14 12 annual growth 12 over the past 10 five years 10 8 8 Dec-2013 Dec-2014 Dec-2015 Dec-2016 Dec-2017 Dec-2018 6 Onex Corporation December 31, 2018 5 HOW WE ARE INVESTED All dollar amounts, unless otherwise noted, are in millions of U.S. dollars. This How We Are Invested schedule details Onex’ $6.4 billion of capital and provides private company perfor- mance and public company ownership information. This schedule includes values for Onex’ investments in controlled companies based on estimated fair values prepared by management. The estimated fair values for investments are presented net of management incentive programs. The presentation of controlled investments in this manner is a non-GAAP financial measure. This schedule may be used by investors as a means of compari- son to the fair values they may prepare for Onex and Onex’ investments. While the schedule provides a snapshot of Onex’ assets, it does not fully reflect the value of Onex’ asset management business as it includes only an esti- mate of the unrealized carried interest due to Onex based on the current estimated fair values of the investments and allocates no value to future management company income.