Exhibit 99.1 Allegro MicroSystems Reports Fourth Quarter and Fiscal Year 2024 Results – Full Year 2024 Sales Increase 8% to a Record $1.05 Billion –38% Growth in E-Mobility Drives 17% Year-over-Year Increase in Full Year 2024 Automotive Sales – Manchester, NH, May 9, 2024 – Allegro MicroSystems, Inc. (“Allegro” or the “Company”) (Nasdaq:ALGM), a global leader in power and sensing semiconductor solutions for motion control and energy efficient systems, today announced financial results for its fourth quarter ...