Mayr in a German surname which may refer to:
- Ernst Walter Mayr (1904–2005), German American evolutionary biologist
- Gustav Mayr (1830–1908), Austrian entomologist (Hymenoptera)
- Simon Marius (1573–1624), German astronomer
- Johann Simon Mayr (1763–1845), German composer
- Karl Mayr (1883–1945), German politician and officer
- Michael Mayr (1864–1922), Austrian historian, politician and Bundeskanzler (1920/21)
- Rupert Ignaz Mayr (1646–1712), German composer (Wikipedia article in German)
- Andrea Mayr (born 1979), Austrian female long-distance runner
- Andreas Mayr (born 1983), German cyclist
- Bernadette Mayr (born 1952), German female quilt-artist
- Bernhard Mayr (born 1984), German wrestler
- Ernst Wilhelm Mayr (born 1950), German computer scientist
- Franz Xaver Mayr (1875–1965), Begründer der nach ihm benannten Diagnostik and Therapie
- Georg Mayr (born 1841), German statistician and economist
- Heinrich Mayr (1856–1911), German Forstmann and botanist
- Hans Mayr
- Hans Mayr (German politician) (born 1921), German politician (SPD)
- Hans Mayr (Austrian politician) (1928–2006), Austrian politician (SPÖ)
- Jörg Mayr (born 1970), German Eishockeyspieler
- Johann von Mayr (? - 1759), Prussian Befehlshaber eines Freibataillons
- Josef Mayr-Nusser (1910–1945), Südtiroler Märtyrer
- Karl Sigmund Mayr (1906–1978), German economist and politician (CSU)
- Peter Mayr (1767–1810), Tyrolese Wirt and Freiheitskämpfer
- Philipp Benitius Mayr OSM (1760–1826), Austrian Servitenpater and Professor
- Rosl Mayr (1895–1981), German female Volkschauspieler
- Mayr-Melnhof AG, a Vienna-based company