NEWS RELEASE Exhibit 99.1 MATTEL REPORTS FIRST QUARTER 2024 FINANCIAL RESULTS First Quarter 2024 Highlights Versus Prior Year • Net Sales of $810 million, down 1% as reported and in constant currency • Gross Margin of 48.0%, an increase of 800 basis points; Adjusted Gross Margin of 48.3%, an increase of 830 basis points • Operating Loss of $36 million, an improvement of $80 million; Adjusted Operating Loss of $23 million, an improvement of $63 million • Net Loss of $28 million, an improvement of $78 million ...