Ralph Hammerthaler (born 2 December 1965) is a German writer.
Born in Wasserburg am Inn, Hammerthaler studied in Munich, Berlin and Jena and wrote a dissertation on political public sphere in sociology.
After eight years as a writer in the feature section of the Süddeutsche Zeitung, including two years as culture editor in Berlin, he began writing novels, stories and essays as well as plays and opera libretti.
His libretto Die Bestmannoper about the Nazi war criminal Alois Brunner was set to music by Alex Nowitz and premiered in 2006 in the presence of Serge and Beate Klarsfeld.
He was a guest dramaturge at the Schaubühne am Lehniner Platz and he is Socio Honorario of the Teatro Sombrero Azul in Mexico City.