Feistmantl or Feistmantel is a German surname. Notable people with the surname include:
Josef Feistmantl (1939–2019), Austrian luger Karl Feistmantl, Austrian luger Karel Feistmantel (1819–1885), Czech geologist Otokar Feistmantel (1848-1891), Czech-Austrian geologist and paleontologist
See also Feistmantel Valley, fossiliferous valley in Antarctica, named after Otokar Feistmantel