From Wikipedia, the free encyclopedia. Frank Shamrock (born Frank Alisio Juarez, III; December 8, 1972) is a retired mixed martial arts fighter.

Shamrock was the first to hold the UFC Middleweight Championship (later renamed the UFC Light Heavyweight Championship) and retired as the four-time defending undefeated champion. Shamrock was widely credited as being the #1 ranked pound for pound fighter in the world during his reign as the UFC Middleweight Champion. Shamrock has also won numerous titles in other mixed martial arts organizations, including the interim King of Pancrase title, the WEC Light Heavyweight Championship, and the Strikeforce Middleweight Championship.