Santiago Lorenzo (born May 4, 1978 in Buenos Aires) is a retired decathlete from Argentina who competed for his native country at the 2004 Summer Olympics in Athens, Greece.

He was a two-time Pac-10 decathlon champion, winning first in 2001, and then again in 2003, when he helped the Ducks capture their first conference team title in 13 years.

Santiago Lorenzo moved to the United States in 1999 with a scholarship to run track for the University of Oregon.

He conducted research studies investigating mechanisms of shortness of breath with exertion in obese individuals until June 2012.

Currently he resides in Sarasota, Florida, with his wife and two children, where he is a full-time faculty member at Lake Erie College of Osteopathic Medicine.