Thijs van Leer (pronounced: /tɛis vɑn leːr/; born 31 March 1948) is a Dutch musician, singer, songwriter, composer and producer, best known as the founding member of the rock band Focus as its primary vocalist, keyboardist, and flautist. Born and raised in Amsterdam among a musical family, van Leer took up the piano and flute as a child and pursued them at university and music academies.
From 1967 to 1969, van Leer performed in a theatre cabaret act headed by Ramses Shaffy as his backing vocalist and musician, recorded singles as a solo artist, and produced, arranged, and conducted music for Bojoura. He formed Trio Thijs van Leer, a three-piece rock band which evolved into Focus in late 1969 following the addition of guitarist Jan Akkerman. Focus achieved international success following the release of Moving Waves (1971) and its lead single, "Hocus Pocus", which features van Leer's yodelling and whistling. After several albums with various line-ups, van Leer disbanded Focus in 1978; he reformed the band in 2002.
Van Leer achieved success as a solo artist in the Netherlands. His first two solo albums featuring classical flute, Introspection (1972) and Introspection 2 (1975), sold an estimated 1.2 million copies. He has collaborated with various artists, and continues to release albums and perform in various capacities. In 2008, van Leer was made a Knight of the Order of Orange-Nassau for special services to music.