Thalia da Silva Costa (born 30 May 1997) is a Brazilian rugby union and sevens player. She represented Brazil in sevens at the 2020 and 2024 Summer Olympics.
Her twin sister Thalita Costa also plays rugby sevens for Brazil. They were born in São LuÃÂs.
Costa was named in the Brazil squad for the Rugby sevens at the 2020 Summer Olympics. She represented Brazil at the 2022 Rugby World Cup Sevens in Cape Town, they placed eleventh overall.
She competed for Brazil at the 2024 Summer Olympics in Paris. In May 2025, she was named in the SVNS Dream Team for 2024-25. In March 2026, she scored a brace as Brazil defeated Kenya 24-12 to earn a place from SVNS Division 2 into the world championship finals of the 2025âÂÂ26 SVNS season.