Manfred Trojahn (born 22 October 1949) is a German composer, flutist, conductor and writer.
Manfred Trojahn was born in Cremlingen in Lower Saxony and began his musical studies in 1966 in orchestra music at the music school of the city of Braunschweig. After graduating in 1970 he concluded his studies as a flutist at the Hochschule für Musik und Theater Hamburg with Karlheinz Zöller. From 1971 he studied composition with Diether de la Motte. He also studied with György Ligeti, conducting with Albert Bittner. Since 1991 he is professor for composition at the Robert Schumann Hochschule in Düsseldorf. From 2004 until 2006 he was President of the Deutscher Komponistenverband (German Composers Association); since 2008 he is vice-director of the music section of the Academy of Fine Arts in Berlin.
Manfred Trojahn is married to the stage- and costume-designer Dietlind Konold. He lives in Düsseldorf and Paris.
His works have been published by Bärenreiter and Sikorski.
Manfred Trojahn: Schriften zur Musik, Ed. by Hans-Joachim Wagner, Frankfurt/M und Basel 2006 (Stroemfeld) ISBN 3-87877-945-3
Among Trojahn's students in composition are Oscar van Dillen, Matthias Pintscher and Daniel Hensel.