Born in Pordenone, Italy, Jackson is the son of American parents. His father served at Aviano Air Base before the family moved to England and later the United States. They lived in various places around the country, including North Dakota, Georgia, and Florida, before finally settling in Colorado Springs, Colorado, when Jackson was in sixth grade. It was here that he began to hone his basketball skills, attending General William J. Palmer High School and eventually winning the 2007-2008 Gatorade Colorado Boys' Basketball Player of the Year award.

While at Palmer High School, Jackson made a name for himself as one of the best players in the state. He helped lead his team to the state championship game, scoring 31 points in the final game despite suffering from a sprained ankle. He was also named to the Colorado Springs Gazette's all-area team three times and was a first-team all-state selection in his senior year.

After high school, Jackson attended Boston College, where he played basketball for three years before entering the NBA draft. He was selected by the Oklahoma City Thunder in the first round of the 2011 draft, and he has since played for several other NBA teams, including the Detroit Pistons and the LA Clippers.

In addition to his success on the court, Jackson has also made headlines for his philanthropic work. He is a supporter of the Make-A-Wish Foundation and has also worked with the Boys & Girls Clubs of America, among other organizations.