Jack, a composed charmer, is the father of Dylan McKay, who he had with his ex-wife Iris, and Erica McKay, his younger child with a woman named Suzanne Steele. In the tenth season it was revealed that his death had been faked and for years he had been in Witness Protection living under the alias Eddie Waitkus and that he has a new wife named Lisa and a son named Jack.
Throughout the course of the series, Jack became known as a wealthy businessman with former ties to criminal activity. His relationship with Dylan became strained following the divorce with Iris and his son's growth into a teenager. Jack later served a term in prison, only to find that Dylan had grown even more distant upon his release. Time and sentiment would soon make the two close once again, however, and eventually their bond appeared to be fully healed.
As part of his involvement in the FBI Witness Protection Program, Jack's death was staged with a car bomb. This event led his enemies—and Dylan—to believe he was dead. Years later, Steve Sanders spotted Jack amidst a group of people in a news video, and quickly brought this to Dylan's attention. After a stunned Dylan initially tried to locate him, Jack eventually came forth and explained the longtime situation with the FBI. Jack had also remarried at this point, and was planning to leave the Witness Protection Program. Dylan, however, convinced him to remain under FBI protection. After the two exchanged farewells, Jack returned to Arizona.
- Jack first made an appearance in the tenth episode of the first season played by Terence Ford. Josh Taylor's first appearance as Jack McKay was in the second season.