Cinna Lomnitz Aronsfrau (4 May 1925 – 7 July 2016) was a German-born Chilean-Mexican geophysicist of Jewish descent. He known for his work in the fields of rock mechanics and seismology.
Lomnitz was born in Cologne, Germany. He graduated as engineer from the University of Chile in 1948. He then studied with Karl von Terzaghi in Harvard University and obtained a Master's degree in soil mechanics there.
He became editor of the journal Geofísica Internacional in 1990. He is the father of Claudio Lomnitz. Lomnitz died in 2016 at the age of 91.