Heinrich Gustav Reichenbach (Dresden, 3 January 1823 – Hamburg, 6 May 1889) was a botanist and the foremost German orchidologist of the 19th century.

His father Heinrich Gottlieb Ludwig Reichenbach (author of Icones Florae Germanicae et Helveticae) was also a well-known botanist.

His immense herbarium and library were bequeathed to the 'Naturhistorisches Museum' in Vienna, Austria (instead, as expected, to the Kew Gardens), on the condition that it would not be consulted during the first 25 years after his death.

Reichenbach probably acted this way out of resentment of the appointment of Robert Allen Rolfe, a self-taught orchid expert, as the top taxonomist at Kew.

In 1886, Frederick Sander commissioned Henry George Moon (1857-1905), a pure colourist, to paint 192 watercolour plates of orchids with descriptions by Reichenbach (1888-1894).