Nesmith made the announcement in a statement posted on Instagram.
"I have decided to enter the 2020 NBA Draft and intend to hire an agent," Nesmith wrote as part of his post.
"I am so grateful for what life has brought me so far and I cannot wait for this next step in my journey."
The 6-foot-6, 213-pound Nesmith averaged 23 points and 4.9 rebounds in his sophomore season, making 52% of his 3-pointers. His season was cut short after only 14 games because of a stress fracture in his foot that required surgery in late January.
He is the 17th-ranked prospect in ESPN's draft prospect rankings.
The NBA draft is scheduled for June 25, but following worldwide suspensions of basketball activities amid the coronavirus outbreak, NBA front-office executives and others in the industry told ESPN they are bracing for the potential impact of a delayed 2020 draft with a heavily reduced pre-draft process.