In August 1993, Ray and his brother Booker T went to World Championship Wrestling (WCW) and changed their team name to Harlem Heat. Initially, Ray was known as Kane while Booker became Kole. They were then billed from Harlem. They became heels and were on Harley Race and Col. Rob Parker's team in the War Games at Fall Brawl on September 19, 1993, with Vader and Sid Vicious against Sting, Davey Boy Smith, Dustin Rhodes and The Shockmaster. They lost the match when Shockmaster forced Booker (Kole) to submit.
In 1994, they hired Sister Sherri as their manager and changed their names to Booker T and Stevie Ray. They feuded with Stars and Stripes (The Patriot and Buff Bagwell) and won the WCW Tag Team Titles for the first time.
From there, they feuded with The Nasty Boys (Jerry Sags and Brian Knobs) and got into a feud with Col. Parker's "Stud Stable" of Dick Slater and Bunkhouse Buck where Parker and Sherri were carrying on a love affair. During this time, Stevie and Booker lost the titles to the Nasty Boys, regained them, then lost them to Slater and Buck and regained them again. They eventually gained Parker as a manager as he abandoned Slater and Buck to be with Sherri. Harlem Heat won the WCW World Tag Team Championship three times in 1995, trading the titles with The American Males (Bagwell and Scotty Riggs) in the early fall.
They had brief feuds with Lex Luger and Sting, trading the titles back and forth in early 1996 and The Road Warriors before starting a long feud with Rick and Scott Steiner in 1996. In October, they lost their titles to The Outsiders (Kevin Nash and Scott Hall) when Nash used Parker's cane to attack Stevie. They would then fire the Colonel, beat him up, turn face, and enter into a brief feud against Parker's newest team The Amazing French Canadians, a feud they would win.
In 1997, they feuded with Public Enemy (Johnny Grunge and Rocco Rock), The Steiners and the New World Order. In the summer of 1997, they fired Sherri and added a new manager, Jacqueline. They were briefly put out of action by the nWo and returned to feud with The Faces of Fear (Meng and The Barbarian).
As 1998 started to roll around, Stevie had to take some time off from WCW from January to June. Meanwhile, Booker T would go on to win WCW World Television Championship. Through the association with his brother, he would gain his only singles title in WCW, as when Booker took time off with an injury as Television Champion from July to October, Stevie got a "power of attorney" to defend the belt for Booker. He then engaged in a short feud with Chavo Guerrero, Jr. over the right to defend the belt before dropping it to Chris Jericho afterwards.
By June 1998, Stevie Ray had returned to the ring, and the powerful gang-like faction of the nWo had been split into two: Hollywood Hogan's nWo Hollywood and Kevin Nash's nWo Wolfpac. Stevie Ray would be offered a spot in nWo Hollywood, but was hesitant at first. He would join the "black & white" in August, effectively turning him heel.
Although this would make Stevie Ray known for using dirty tactics and a strength-in-numbers mentality, his brother, Booker, showed little resentment and respected Stevie Ray's decision to be a part of the nWo, and they were able to peacefully co-exist. Meanwhile, Booker was steadily gaining popularity as a face, climbing the ranks of the WCW roster and winning championship titles.
During his tenure with the nWo, Stevie Ray would tag team with the likes of Horace Hogan and Scott Norton as well as performing in singles competition, often with Vincent at ringside. Alongside Hollywood Hogan and Bret Hart, he also participated in the War Games of Fall Brawl 1998. The slapjack became known as Stevie Ray's trademark weapon which he would frequently use to knock an opponent unconscious, typically when the referee was distracted.
By early 1999, both nWo factions had fused back together, but members of nWo Hollywood started bickering over who the leader of the sub-faction was. Hollywood Hogan began telling various members in private that he had granted them official leadership, causing confusion and friction between members. Not long after, Stevie Ray won the leadership role in a 4-man battle royal on the April 5, 1999 episode of WCW Monday Nitro, defeating Horace Hogan, Brian Adams, and Vincent.
As tension grew between members of nWo Hollywood, Stevie Ray started helping Booker T during his matches. As Booker was getting ganged up on in July, the two reunited Harlem Heat. They began feuding with Barry and Kendall Windham as well as The Jersey Triad of Diamond Dallas Page, Chris Kanyon and Bam Bam Bigelow. They went on to win the Tag Titles three more times, making them 10 time champions.
By late 1999, Midnight had joined Harlem Heat. Stevie resented her help and started disputing with Booker over her. He eventually challenged Midnight in a match that would decide whether or not she would stay with Harlem Heat. After being defeated with a surprise small package, Stevie Ray would turn on both Booker and Midnight to form Harlem Heat, Inc. with Big T, Kash and J. Biggs. They won the rights to the Harlem Heat name in a match with Big T against Booker on February 20, 2000 at SuperBrawl X.
In May, Stevie split from Big T, Kash and Biggs (who all left WCW) and helped Booker T out of a jam. He then retired from in-ring competition to become a color commentator for WCW Thunder.
As a commentator, Stevie referred to all of the women as "yaks" and coined his catchphrase "Suckas gots to know!" He also provided in-depth analysis from a wrestler's point of view during matches and constantly criticized wrestlers for mistakes made in the ring.
Stevie came back for one more WCW match (a title vs. career match) for the WCW World Heavyweight Championship against Scott Steiner on the November 27, 2000 edition of WCW Monday Nitro, which he lost.
In April 2013, Stevie Ray inducted Booker T into the WWE Hall of Fame.
In 2019, Stevie Ray himself, as well as Booker T once again, would be inducted into the WWE Hall of Fame as part of Harlem Heat.