He won a silver medal in the 100-meter butterfly at the 2008 Summer Olympics in a historic race with American swimmer Michael Phelps.

Born in Anaheim, California and a citizen of both Serbia and the United States, he attended Tustin High School in Tustin, California, where he set four CIF records and a national high school mark in the 50 yd freestyle.

[1] While swimming for the University of California, Berkeley and training with Mike Bottom, Čavić set a new school and Pac-10 record in the 100 yd butterfly (45.44 s).

On December 14, 2007, the sprinter defended his European championship again in the 100 m butterfly in Debrecen, finishing at 50.53 seconds.

At the age of 16, Čavić represented Yugoslavia at the 2000 Summer Olympics in Sydney, Australia in the 100 m butterfly (disqualified) and 100 backstroke – 42nd – 58.25 s.[12] Čavić represented Serbia and Montenegro at the 2004 Summer Olympics in Athens, Greece in the 100 m butterfly, 50 m freestyle and the 100 m freestyle.

[14] Čavić represented Serbia at the 2008 Summer Olympics in Beijing, People's Republic of China in two swimming events.

It was later confirmed by the FINA and Omega timekeeping officials that Čavić indeed arrived first but it was Phelps who, in the milliseconds after touching the wall, applied more force to trigger an electronic touchpad first.

[13] Čavić represented Serbia at the 2012 Summer Olympics in London, England, making it his sporting finale.