Before the start of 2016-17, Tatum missed 8 games due to a foot injury. On December 3, 2016 in his Duke debut, Tatum recorded 10 points in a 94–55 win over Maine. On December 6, 2016, Tatum tallied 22 points & 8 rebounds in an 84–74 victory over Florida at the Jimmy V Classic. On December 12, 2016, Tatum was named ACC freshman of the week. On December 21, 2016, Tatum scored 18 points, 8 rebounds, and 4 blocks in a 72–61 win over Elon. On January 4, 2017, Tatum scored 19 points in a 110–57 victory over Georgia Tech. On January 7, he recorded 22 points and 6 rebounds in a 93–82 victory over Boston College. On January 21, Tatum scored 14 in a 70–58 win over Miami. On February 13, Tatum earned his second ACC freshman of the week honor. On February 15, he scored a season-high 28 points and had 8 rebounds in a 65–55 victory against Virginia. On February 18, 2017, Tatum scored 19 points in a 99–94 victory over Wake Forest. As the fifth seed in the ACC Tournament, Duke defeated Clemson in the second round and Louisville in the quarterfinals. On March 10, Tatum scored 24 points in a win over rival North Carolina in the semifinals. On March 11, Tatum tallied 19 points and 8 rebounds in a 75–69 victory against the Notre Dame Fighting Irish, earning the Blue Devils the ACC Tournament Championship.