Bayer is a German multinational pharmaceutical and biotechnology company.
Bayer may refer to: a native or inhabitant of the Free State of Bavaria (Freistaat Bayern) Bayer (crater), a lunar crater Bayer filter, a color filter mosaic also known as a Bayer pattern or Bayer mask, used in digital camera image sensors Bayer designation for star names KFC Uerdingen 05, formerly known as FC Bayer 05 Uerdingen, a German football club Bayer Leverkusen, a German sports and football club Bayer 04 Leverkusen, a German woman's handball club Bayer Esporte Clube, a Brazilian football club Baeyer's reagent, a mild oxidation reagent used in organic chemistry Bayer (surname), list of people with this name
See also Beyer, a surname Buyer