www.smurfitwestrock.com Exhibit 99.1 Dublin – July 30, 2025 – Smurfit Westrock plc (NYSE: SW, LSE: SWR) today announced the financial results for the second quarter ended June 30, 2025. Key points: Smurfit Westrock plc's performance for the three months ended June 30, 2025 and 2024 (in millions, except margins): | | | | June 30, | | | --- | --- | --- | --- | --- | | | 2025 | | | 2024 | | Net Sales | $| 7,940 |$ | 2,969 | | Net (Loss) Income | $| (26) |$ | 132 | | Net (Loss) Income Margin | | (0.3%) | | ...