Tuuli Petäjä-Sirén (born 9 November 1983 in Espoo) is a Finnish windsurfer.
She won a silver medal at the 2012 Summer Olympics in the women's RS:X.She was chosen as athlete of the year in Finland in 2012.At the opening ceremony of the 2016 Summer Olympics Petäjä-Sirén was chosen to carry the Finnish flag.