Klaas de Vries was born in Terneuzen on July 15, 1944.
He studied piano and composition at the Rotterdam Conservatory of Music and continued his composition studies with Otto Ketting at the Royal Conservatory of Music in The Hague. After winning the prize for composition in 1974 he studied with Milko Kelemen in West Germany.
From 1972 to 1981 De Vries taught theory at the Twents Conservatorium. Since 1979 he teaches analysis, instrumentation and composition at the Rotterdam Conservatorium. He is one of the founders of the 'Rotterdam School'.
Since 1968 a great diversity of scorings has been added to his oeuvre, performed by the Rotterdam Philharmonic Orchestra, the Hague Philharmonic Orchestra, the Netherlands Saxophone Quartet (Twee Koralen), Schoenberg Ensemble (Eclips) and others. During the Holland Festival 1996 his most important composition, the "scenic oratorio" A king, riding was first performed. For the National Youth Orchestra he wrote Antagonistische ode (2000) for the concert series Symphonic Variations of Europe.
In 1984 he was awarded the Matthijs Vermeulen Prize for Discantus, written in 1982 for the Netherlands Students Orchestra. In 1998 he was awarded the Matthijs Vermeulen Prize again, for A king, riding and Interludium for string orchestra.