Dirk Jens Nonnenmacher (born June 3, 1963) was the CEO and chairman of HSH Nordbank.
A trained mathematician, Nonnenmacher worked for several private banks before joining HSH Nordbank in 2007.
He became chairman in November 2008, succeeding Hans Berger and left the bank in March 2011.
Nonnenmacher studied mathematics and medicine, before receiving his Ph.D.