Johann Mayer

Johann Mayer may refer to:
 * Johann Tobias Mayer (1752–1830), German physicist
 * Johann Mayer (serial killer) (1886–1923), German serial killer
 * Johann Christoph Andreas Mayer (1747–1801), German anatomist
 * Johann Friedrich Mayer (theologian) (1650–1712), German Lutheran theologian and professor of theology
 * Johann Friedrich Mayer (agriculturist) (1719–1798), German Reformed pastor and agricultural reformer
 * Johann Prokop Mayer (1737–1804), Austrian naturalist and botanist