|Parents:|| Danny Reagan (father)|
Linda Reagan (mother, deceased)
|Sibling(s):||Sean Reagan (younger)|
|Grandparents:|| Frank Reagan (paternal grandfather)|
Mary Reagan (paternal grandmother, deceased)
|Great-Grandparents:|| Henry Reagan (paternal great-grandfather)|
Betty Reagan (paternal great-grandmother, deceased)
|Cousins:||Nicky Reagan-Boyle (via Erin)|
|Played by:||Tony Terraciano|
Born in 2000. Jack and his brother, Sean Reagan, both play a variety of sports including lacrosse, football and soccer. He attends private Catholic school with his brother. Both have also learned some self-defense from their father.
After witnessing a shooting, Jack became upset and came home from school early, something he never does. In an attempt to help him, Danny gave him a basic gun safety course.
Jack has failed one class, Algebra, and was recommended summer school or tutors. He skipped school on one occasion to go to a party where he was drinking even though he is underage. Linda found a video made of him at that party on his phone and told Danny who took his phone away, lecturing him about stupid choices.
He has a crush on a girl named Charlotte who he took on a date to an ice skating rink.