Exhibit 99.1 Silicon Motion Announces Results for the Period Ended December 31, 2023 NEWS RELEASE Business Highlights • Fourth quarter sales increased 17% Q/Q and increased 1% Y/Y • SSD controller sales: 4Q increased 15% to 20% Q/Q and increased 0% to 5% Y/Y • eMMC+UFS controller sales: 4Q increased 25% to 30% Q/Q and increased 20% to 25% Y/Y • SSD solutions sales: 4Q decreased 5% to 10% Q/Q and decreased 45% to 50% Y/Y • Announced annual cash dividend of $2.00 per ADS Financial Highlights 4Q 2023 GAAP 4Q 2 ...