The enzyme galactonate dehydratase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is <small>D</small>-galactonate hydro-lyase (2-dehydro-3-deoxy-<small>D</small>-alactonate-forming). Other names in common use include <small>D</small>-galactonate dehydrase, <small>D</small>-galactonate dehydratase, and <small>D</small>-galactonate hydro-lyase. This enzyme participates in galactose metabolism.