Exhibit 99.1

onsemi First Quarter 2023 Results Exceed Expectations

Automotive and Industrial end-markets contribute record 79% of revenue

Scottsdale, Ariz, – May 1, 2023 – onsemi (the “Company”) (Nasdaq: ON) today announced results for the first quarter of 2023 with the following highlights:

“We continued our momentum with first quarter results exceeding expectations despite macroeconomic uncertainties. Our accelerating Silicon Carbide manufacturing output exceeded our internal plans and enabled us to nearly double our silicon carbide revenue quarter-over-quarter, and we grew both ADAS and energy infrastructure revenue by approximately 50% year-over-year. As secular tailwinds propel our business, we are prudently managing our operations to deliver consistent and predictable results in the current market environment,” said Hassane El-Khoury, President and CEO of onsemi.

Selected financial results for the quarter are shown below with comparable periods (unaudited):

1

SECOND QUARTER 2023 OUTLOOK

The following table outlines onsemi’s projected second quarter of 2023 GAAP and non-GAAP outlook.

2

TELECONFERENCE

onsemi will host a conference call for the financial community at 9 a.m. Eastern Time (ET) on May 1, 2023 to discuss this announcement and onsemi’s 2023 first 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 by pre-registering here .

3

About onsemi

onsemi (Nasdaq: ON) is driving disruptive innovations to help build a better future. With a focus on automotive and industrial end-markets, the company is accelerating change in megatrends such as vehicle electrification and safety, sustainable energy grids, industrial automation, and 5G and cloud infrastructure. onsemi offers a highly differentiated and innovative product portfolio, delivering intelligent power and sensing technologies that solve the world’s most complex challenges and leads the way to creating a safer, cleaner, and smarter world. onsemi is recognized as a Fortune 500^® company and included in the S&P 500^® index. Learn more about onsemi at www.onsemi.com.

# # #

onsemi and the onsemi logo are 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 includes “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 onsemi, including financial guidance for the second quarter of 2023. Forward-looking statements are often characterized by the use of words such as “believes,” “estimates,” “expects,” “projects,” “may,” “will,” “intends,” “plans,” “anticipates,” “should” or similar expressions 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. Certain factors that could affect our future results or events are described under Part I, Item 1A “Risk Factors” in the 2022 Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on February 6, 2023 (the “2022 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, which speaks only as of the date made, except as may be required by law. Investing in our securities involves a high degree of risk and uncertainty, and you should carefully consider the trends, risks and uncertainties described in this document, our 2022 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 us or persons acting on our behalf are expressly qualified in their entirety by this cautionary statement.

4

ON SEMICONDUCTOR CORPORATION

UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS

(in millions, except per share data)

5

ON SEMICONDUCTOR CORPORATION

UNAUDITED CONSOLIDATED BALANCE SHEETS

(in millions)

6

ON SEMICONDUCTOR CORPORATION

UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS

(in millions)

7

ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES

(in millions, except per share and percentage data)

8

ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES (Continued)

(in millions, except per share and percentage data)

Certain of the amounts in the above tables may not total due to rounding of individual amounts.

Total share-based compensation related to restricted stock units, stock grant awards and the employee stock purchase plan is included below:

9

ON SEMICONDUCTOR CORPORATION

RECONCILIATION OF GAAP VERSUS NON-GAAP DISCLOSURES (Continued)

(in millions, except per share and percentage data)

SUPPLEMENTAL FINANCIAL DATA

10

NON-GAAP MEASURES

To supplement the consolidated financial results prepared in accordance with GAAP, onsemi uses certain non-GAAP measures, which are adjusted from the most directly comparable GAAP measures to exclude items related to the amortization of acquisition-related intangibles, expensing of appraised inventory fair market value step-up, inventory valuation adjustments, in-process research and development expenses, restructuring, asset impairments and other, net, goodwill impairment charges, gains and losses on debt prepayment, non-cash interest expense, actuarial (gains) losses on pension plans and other pension benefits, third party acquisition and divestiture-related costs, tax impact of these items and certain other non-recurring items, as necessary. Management does not consider the effects of these items in evaluating the core operational activities of onsemi. Management uses these non-GAAP measures internally to make strategic decisions, forecast future results and evaluate onsemi’s current performance. In addition, the Company believes that most analysts covering onsemi use the non-GAAP measures to evaluate onsemi’s performance. Given management’s and other relevant parties’ use of these non-GAAP measures, onsemi believes these measures are important to investors in understanding onsemi’s current and future operating results as seen through the eyes of management. In addition, management believes these non-GAAP measures are useful to investors in enabling them to better assess changes in onsemi’s core business across different time periods. These non-GAAP measures are not prepared in accordance with, and should not be considered alternatives or necessarily superior to, GAAP financial data and may be different from non-GAAP measures used by other companies. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures, even if they have similar names.

Non-GAAP Revenue

The use of non-GAAP revenue allows management to evaluate, among other things, the revenue from the Company’s core businesses and trends across different reporting periods on a consistent basis, independent of special items. In addition, non- GAAP revenue is an important component of management’s internal performance measurement and incentive and reward process as it is used to assess the current and historical financial results of the business and for strategic decision making, preparing budgets, obtaining targets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate the Company’s revenue generation performance relative to the direct costs of operations of onsemi’s core businesses.

Non-GAAP Gross Profit and Gross Margin

The use of non-GAAP gross profit and gross margin allows management to evaluate, among other things, the gross margin and gross profit of the Company’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including, generally speaking, expensing of appraised inventory fair market value step-up, impact of business wind down and non-recurring facility costs. In addition, it is an important component of management’s internal performance measurement and incentive and reward process as it is used to assess the current and historical financial results of the business and for strategic decision making, preparing budgets, obtaining targets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate our revenue generation performance relative to the direct costs of revenue of onsemi’s core businesses.

Non-GAAP Operating Income and Operating Margin

The use of non-GAAP operating income and operating margin allows management to evaluate, among other things, the operating margin and operating income of the Company’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including, generally speaking, expensing of appraised inventory fair market value step-up, impact of business wind down, non-recurring facility costs, amortization and impairments of intangible assets, third party acquisition and divestiture-related costs, restructuring charges and certain other special items as necessary. In addition, it is an important component of management’s internal performance measurement and incentive and reward process as it is used to assess the current and historical financial results of the business and for strategic decision making, preparing budgets, obtaining targets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate the Company’s revenue generation performance relative to the direct costs of operations of onsemi’s core businesses.

Non-GAAP Net Income Attributable to onsemi and Non-GAAP Diluted Earnings Per Share

The use of non-GAAP net income attributable to onsemi and non-GAAP diluted earnings per share allows management to evaluate the operating results of onsemi’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including, generally, the amortization and impairments of intangible assets, expensing of appraised inventory fair market value step-up, impact of business wind down, non-recurring facility costs, restructuring, gains and losses on debt prepayment, non-cash interest expense, actuarial (gains) losses on pension plans and

11

NON-GAAP MEASURES (Continued)

other pension benefits, third party acquisition and divestiture-related costs, discrete tax items and other non-GAAP tax adjustments and certain other special items, as necessary. In addition, these items are important components of management’s internal performance measurement and incentive and reward process, as they are used to assess the current and historical financial results of the business and for strategic decision making, preparing budgets, setting targets and forecasting future results. Management presents these non-GAAP financial measures to enable investors and analysts to understand the results of operations of onsemi’s core businesses and, to the extent comparable, to compare our results of operations on a more consistent basis against those of other companies in our industry.

Free Cash Flow

The use of free cash flow allows management to evaluate, among other things, the ability of the Company to make interest or principal payments on its debt. Free cash flow is defined as the difference between cash flow from operating activities and capital expenditures disclosed under investing activities in the consolidated statement of cash flows. Free cash flow is not an alternative to cash flow from operating activities as a measure of liquidity. It is an important component of management’s internal performance measurement and incentive and reward process as it is used to assess the current and historical financial results of the business and for strategic decision making, preparing budgets, obtaining targets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate our revenue generation performance relative to the direct costs of operations of onsemi’s core businesses.

Non-GAAP Diluted Share Count

The use of non-GAAP diluted share count allows management to evaluate, among other things, the potential dilution due to the outstanding restricted stock units excluding the dilution from the convertible notes that is covered by hedging activity up to a certain threshold. In periods when the quarterly average stock price per share exceeds $20.72 for the 1.625% Notes, $52.97 for the 0% Notes, and $103.87 for the 0.50% Notes, the non-GAAP diluted share count includes the anti-dilutive impact of the Company’s hedge transactions issued concurrently with the 1.625% Notes, the 0% Notes, and the 0.50% Notes respectively. At an average stock price per share between $20.72 and $30.70 for the 1.625% Notes, $52.97 and $74.34 for the 0% Notes, and $103.87 and $156.78 for the 0.50% Notes, the hedging activity offsets the potentially dilutive effect of the 1.625% Notes, the 0% Notes, and the 0.50% Notes, respectively. In periods when the quarterly average stock price exceeds $30.70 for the 1.625% Notes, $74.34 for the 0% Notes, and $156.78 for the 0.50% Notes, the dilutive impact of the warrants issued concurrently with such notes are included in the diluted shares outstanding.

12