Jackson made the announcement on Twitter.
Jackson, a 6-foot-7 small forward, is No. 3 in the ESPN 100 but was the only top-10 prospect still uncommitted entering the late signing period. He took official visits to three schools: Kansas, Michigan State and Arizona. Michigan State was hoping to convince Jackson, a Michigan native, to come back home for college, while Arizona was banking on Jackson's relationship with coach Sean Miller from USA Basketball. Kansas, meanwhile, impressed Jackson on his visit to Allen Fieldhouse.
"I love Coach [Bill] Self," Jackson told ESPN.com last month at the McDonald's All American Game. "I love the way he coaches his players. Pushes them, makes them better. When I took my official visit there, I got this real good feeling that they were all about family. You could really trust people there."
Jackson, who spent his past two seasons at Prolific Prep (California), might make the biggest impact of any freshman in college basketball next season. What sets him apart is his two-way ability and leadership. Jackson is a terrific defender who uses his length and athleticism to guard multiple positions, but he also is an adept passer and is very difficult to contain in transition. ESPN's Chad Ford has Jackson atop his very early 2017 Big Board.
Jackson won three gold medals with USA Basketball, including one in last summer's FIBA U19 World Championship. On a team comprised mostly of college players, Jackson started all seven games and averaged 12.1 points and 7.0 rebounds while also shooting 50 percent from 3-point range.
Kansas has long been in pursuit of Jackson as a replacement for Wayne Selden Jr., who declared for the NBA draft following the 2015-16 season. Jackson will immediately step in at the small forward position, and give Self and the Jayhawks their best NBA prospect since Andrew Wiggins.
Jackson joins a Kansas recruiting class that already includes five-star center Udoka Azubuike and four-star power forward Mitch Lightfoot, both ESPN 100 prospects. The Jayhawks now have the No. 6 recruiting class in 2016.