Émile Pierre-Marie van Ermengem (1851–1932, or 1851–1922 according to some sources) was a Belgian bacteriologist who, in 1895, isolated Clostridium botulinum, the bacterium that causes botulism, from a piece of ham that had poisoned thirty four people.He worked at the University of Ghent.
His sons were the writer Franz Hellens and the art critic François Maret.