Gaertner or Gärtner is a German surname meaning "gardener". Notable people with the surname include:
Karl Friedrich von Gaertner (1772–1850), German botanist known as "C.F.Gaertn." or "Gaertner fils"
Christian Gärtner (1705–1782), German merchant and astronomer, after whom is named:
Gärtner (crater), a crater on the Moon
132445 Gaertner, an asteroid
Joseph Gaertner (1732–1791), German botanist known as "Gaertn."
Friedrich von Gärtner (1791–1847), German architect
Gottfried Gaertner (1754–1825), German botanist known as "G. Gaertn."
Friedrich Gärtner (1824–1905), German architectural painter
Gustav Gärtner (1855–1937), Austrian pathologist
Carl Gaertner (1898–1952), U.S. artist
Belva Gaertner (1885–1965), U.S. cabaret singer and alleged murderer
Georg Gärtner (1920–2013), German soldier
Hildesuse Gärtner (born 1923), German alpine skier
Bertil Gärtner (1924–2009), Swedish Lutheran bishop of Gothenburg
Claus Theo Gärtner (born 1943), German television actor