Karl Kreil (1798–1862) was an Austrian meteorologist and astronomer, born in Ried.

Before university, he was educated at the Benedictine Kremsmünster Abbey, under the astronomer Boniface Schwarzenbrunner.

[1] He was educated at the University of Vienna, where he studied law before devoting himself to astronomy.

He made particularly important studies of terrestrial magnetism, discovering (1841) that it is practically unaffected by the moon and writing Anleitung zu den magnetischen Beobachtungen (second edition, 1858).

From 1849 until his death, he edited the Jahrbuch of the Central Bureau at Vienna.