Exhibit 99.1 Telesat Reports Results for the Quarter and Twelve Months Ended December 31, 2023 OTTAWA, CANADA — March 28, 2024 — Telesat (NASDAQ and TSX: TSAT), one of the world’s largest and most innovative satellite operators, today announced its financial results for the three-month and one-year periods ended December 31, 2023. All amounts are in Canadian dollars and reported under International Financial Reporting Standards (IFRS) unless otherwise noted. “Telesat achieved a great deal in 2023 and I am p ...