Exhibit 99.1

ON Semiconductor Reports Third Quarter 2019 Results

PHOENIX, Ariz. – October 27, 2019 – ON Semiconductor Corporation (Nasdaq: ON) today announced that 2019 third quarter revenue was $1,381.8 million, down approximately 10 percent compared to 2018 third quarter revenue. 2019 third quarter revenue was up approximately 3 percent as compared to 2019 second quarter revenue. Third quarter 2019 GAAP financial results include a one-time charge of approximately $170 million to settle all pending intellectual property litigation with Power Integrations, Inc.

“Business conditions show modest signs of improvement as supply chain inventories have normalized and orders are trending along normal seasonality. However, global macroeconomic and geopolitical uncertainty still persists, and visibility into end-market demands remains limited,” said Keith Jackson, President and CEO of ON Semiconductor. “Despite the current challenges, key drivers powering our business remain intact, and we are seeing strong traction in key areas of strategic thrust. We believe that with our investments in automotive, industrial, and cloud-power markets, and into our operations, we are well positioned to deliver strong revenue and margin performance.”

Third Quarter Results (GAAP)

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Third Quarter Results (Non-GAAP)

Third Quarter Key Cash Flow Items

FOURTH QUARTER 2019 OUTLOOK

Based on product booking trends, backlog levels, and estimated turns levels, the Company anticipates 2019 fourth quarter revenue to be approximately $1,350 to $1,400 million.

GAAP gross margin for fourth quarter of 2019 is expected to be between 35.7 percent and 36.7 percent. Non-GAAP gross margin for fourth quarter of 2019 is expected to be between 35.7 percent and 36.7 percent.

The 2019 fourth quarter outlook also includes anticipated stock-based compensation expense of approximately $17 million to $19 million. Net cash paid for income taxes is expected to be $14 million to $18 million.

The following table outlines ON Semiconductor’s projected fourth quarter of 2019 GAAP and non-GAAP outlook.

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TELECONFERENCE

ON Semiconductor will host a conference call for the financial community at 9 a.m. Eastern Daylight Time (EDT) on October 28, 2019 to discuss this announcement and ON Semiconductor’s 2019 third quarter results. The Company will also provide a real-time audio webcast of the teleconference on the Investor Relations page of its website at http://www.onsemi.com. The webcast replay will be available at this site approximately one hour following the live broadcast and will continue to be available for approximately 30 days following the conference call. Investors and interested parties can also access the conference call via telephone by dialing (877) 356-3762 (U.S./Canada) or (262) 558-6155 (International). In order to join this conference call, you will be required to provide the Conference ID Number, which is 2876804.

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About ON Semiconductor

ON Semiconductor (Nasdaq: ON) is driving energy efficient innovations, empowering customers to reduce global energy use. The Company is a leading supplier of semiconductor-based solutions, offering a comprehensive portfolio of energy efficient power management, analog, sensors, logic, timing, connectivity, discrete, SoC and custom devices. The Company’s products help engineers solve their unique design challenges in automotive, communications, computing, consumer, industrial, medical, aerospace and defense applications. ON Semiconductor operates a responsive, reliable, world-class supply chain and quality program, a robust compliance and ethics program, and a network of manufacturing facilities, sales offices and design centers in key markets throughout North America, Europe and the Asia Pacific regions. For more information, visit http://www.onsemi.com.

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ON Semiconductor and the ON Semiconductor logo are registered trademarks of Semiconductor Components Industries, LLC. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Although the Company references its website in this news release, information on the website is not to be incorporated herein.

This document contains “forward-looking statements,” as that term is defined in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical facts, included or incorporated in this document could be deemed forward-looking statements, particularly statements about the future financial performance of ON Semiconductor, including financial guidance for the year ending December 31, 2019. Forward-looking statements are often characterized by the use of words such as “believes,” “estimates,” “expects,” “projects,” “may,” “will,” “intends,” “plans” or “anticipates” or by discussions of strategy, plans or intentions. All forward-looking statements in this document are made based on our current expectations, forecasts, estimates and assumptions and involve risks, uncertainties and other factors that could cause results or events to differ materially from those expressed in the forward-looking statements. Among these factors are our revenue and operating performance; economic conditions and markets (including current financial conditions); risks related to our ability to meet our assumptions regarding outlook for revenue and gross margin as a percentage of revenue; effects of exchange rate fluctuations; the cyclical nature of the semiconductor industry; changes in demand for our products; changes in inventories at our customers and distributors; risks associated with restructuring actions and workforce reductions; technological and product development risks; enforcement and protection of our intellectual property rights and related risks; risks related to the security of our information systems and secured network; availability of raw materials, electricity, gas, water and other supply chain uncertainties; our ability to effectively shift production to other facilities when required in order to maintain supply continuity for our customers; variable demand and the aggressive pricing environment for semiconductor products; our ability to successfully manufacture in increasing volumes on a cost-effective basis and with acceptable quality for our current products; risks associated with our acquisitions and dispositions generally, including our ability to realize the anticipated benefits of our acquisitions and dispositions, including our acquisition of Quantenna; risks that acquisitions or dispositions may disrupt our current plans and operations, (including the risk of unexpected costs, charges or expenses resulting from acquisitions or dispositions and difficulties arising from integrating and consolidating acquired businesses, our timely filing of financial information with the Securities and Exchange Commission (“SEC”) for acquired businesses and our ability to accurately predict the future financial performance of acquired businesses); competitor actions, including the adverse impact of competitor product announcements; pricing and gross profit pressures; risks associated with the addition of Huawei Technologies Co., Ltd. and its non-U.S. affiliates and subsidiaries, and other customers, to the U.S. Department of Commerce, Bureau of Industry Security Entity List; loss of key customers; risks associated with restructuring actions and workforce reductions; order cancellations or reduced bookings; changes in manufacturing yields; control of costs and expenses and realization of cost savings and synergies from restructurings; the costs to defend against or pursue litigation and the potential significant costs associated with adverse litigation outcomes; risks associated with decisions to expend cash reserves for various uses in accordance with our capital allocation policy such as debt prepayment, stock repurchases or acquisitions rather than to retain such cash for future needs; risks associated with our substantial leverage and restrictive covenants in our debt agreements that may be in place from time to time; risks associated with our worldwide operations, including changes in trade policies, foreign employment and labor matters associated with unions and collective bargaining arrangements, continuing political unrest in markets in which we do significant business, including Hong Kong, as well as man-made and/or natural disasters affecting our operations or financial results; the threat or occurrence of international armed conflict and terrorist activities both in the United States and internationally; risks of changes in U.S. or international tax

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rates or legislation; risks and costs associated with increased and new regulation of corporate governance and disclosure standards; risks related to new legal requirements; and risks and expenses involving environmental or other governmental regulation. Additional factors that could affect our future results or events are described under Part I, Item 1A “Risk Factors” in our 2018 Annual Report on Form 10-K filed with the SEC on February 20, 2019 (our “2018 Form 10-K”) and from time to time in our other SEC reports. Readers are cautioned not to place undue reliance on forward-looking statements. We assume no obligation to update such information, except as may be required by law. You should carefully consider the trends, risks and uncertainties described in this document, our 2018 Form 10-K and other reports filed with or furnished to the SEC before making any investment decision with respect to our securities. If any of these trends, risks or uncertainties actually occurs or continues, our business, financial condition or operating results could be materially adversely affected, the trading prices of our securities could decline, and you could lose all or part of your investment. All forward-looking statements attributable to the Company or persons acting on its behalf are expressly qualified in their entirety by this cautionary statement.

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ON SEMICONDUCTOR CORPORATION

UNAUDITED CONSOLIDATED STATEMENT OF OPERATIONS

(in millions, except per share data)

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ON SEMICONDUCTOR CORPORATION

UNAUDITED CONSOLIDATED BALANCE SHEET

(in millions)

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ON SEMICONDUCTOR CORPORATION

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) ADJUSTED EBITDA AND

NET CASH PROVIDED BY OPERATING ACTIVITIES

(in millions)

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ON SEMICONDUCTOR CORPORATION

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA AND

NET CASH PROVIDED BY OPERATING ACTIVITIES (Continued)

(in millions)

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ON SEMICONDUCTOR CORPORATION

UNAUDITED RECONCILIATION OF NET INCOME (LOSS) TO ADJUSTED EBITDA AND

NET CASH PROVIDED BY OPERATING ACTIVITIES (Continued)

(in millions)

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ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES

(in millions, except per share and percentage data)

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ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES (Continued)

(in millions, except per share and percentage data)

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ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES (Continued)

(in millions, except per share and percentage data)