Guillermo Echevarría Pérez (13 May 1948 – 24 November 2021) was a Mexican swimmer who competed at the 1964 Summer Olympics and the 1968 Summer Olympics. Echevarría was born on 13 May 1948 in Mexico City. He briefly held the world record in the 1500 meter (long course), breaking Mike Burton's record in 1968, before Burton took the record back two months later. Echevarría died on 24 November 2021, at the age of 73.