Born as Phillip Jack Brooks on October 26, 1978 in Chicago, CM Punk is a professional wrestler signed on to World Wrestling Entertainment (WWE), under its RAW brand. There, he rose to fame and became the WWE Intercontinental Champion. He began his career on the professional wrestling independent circuit, and was primarily a member of the Ring of Honor (ROH) roster. With them, he became an ROH Tag Team Champion, ROH World Champion and the first head trainer of the ROH wrestling school. He signed a contract with WWE in 2005, leading to him being sent to its developmental federation, Ohio Valley Wrestling.

Upon the revival of the ECW, CM Punk was moved to the main roster and established himself by his continuous victories in singles competition for six months. A few months later, he won the ECW Championship. In 2008, he was moved from ECW to RAW.

Punk was raised by his father and mother, together with his two younger sisters and his brother, Mike, who was also a pro wrestler. The two had a falling out when Mike embezzled thousands of dollars from the Lunatic Wrestling Federation, where Brooks started out. He began to use the ring name CM Punk when he was put into a tag team named the Chick Magnets. He left soon after, hoping to be more serious about wrestling. After years of training, he became a crowd favorite on ROH and was soon deemed a villain after a feud with Raven.

In 2005, CM Punk became the OVW Television Champion in that WWE developmental territory. The next year, he made his ECW debut during a house show and defeated Stevie Richards. Three years later, he was drafted to the RAW brand and eventually won the World Heavyweight Championship from Edge, who was recently beat down by Batista.

His father was a long-time alcoholic who eventually quit, and CM Punk soon committed himself to abstaining from alcohol consumption. When he studied high school at Lockport Township High School, Illinois, he discovered the hardcore punk music genre and was inspired by the straight edge movement. He soon took on the lifestyle, which is usually employed as a gimmick in his matches and on-screen personality.