Preben Blach (15 December 1920 – 28 March 2007) was a Danish field hockey player.
He competed in the men's tournament at the 1948 Summer Olympics.
He came from a family of hockey players.
His father Arne Blach was also a hockey player and competed in the 1928 Olympics and the 1936 Olympics.
This biographical article relating to a Danish field hockey figure is a stub.