Dewees' bonus with the Cubs was reportedly $1.7 million, according to MLB.com's Jonathan Mayo. The outfielder was a semifinalist for the 2015 USA Baseball Golden Spikes Award, and he was named the Atlantic Sun Conference Player of the Year.
A redshirt sophomore, Dewees batted .422 with 88 runs, 12 doubles, eight triples, 18 home runs and 68 RBIs in 60 games for North Florida this year.
On Thursday, the Cubs also announced the signing of fourth-round pick Darryl Wilson and fifth round pick Tyler Petzmeier. Others to sign include infielder Matt Rose (11th round); left-hander Kyle Twomey (13th), right-hander Kyle Miller (19th), outfielder Alex Bautista (22nd), infielder Sutton Whiting (24th), catcher Ian Rice (29th), catcher Tyler Payne (30th), outfielder Daniel Spingola (31st), right-hander M.T. Minacci (33rd) and outfielder Donnie Cimino (37th).
The Cubs now have signed 14 of their top 20 picks.