The enzyme 4-hydroxyphenylacetate decarboxylase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is 4-(hydroxyphenyl)acetate carboxy-lyase (4-methylphenol-forming). Other names in common use include p-hydroxyphenylacetate decarboxylase, p-Hpd, 4-Hpd, and 4-hydroxyphenylacetate carboxy-lyase.