Pierce, a 6-foot-11 big man out of Scotch Plains (N.J.) Union Catholic, offered up the pledge during an official visit to their campus.
To go with an offer from Dayton, Pierce also had interest from South Carolina, Temple, Seton Hall and a host of others.
Pierce played with the New Jersey Roadrunners during the spring and summer.
The commitment gives Dayton a pair of prospects in their 2017 class. Pierce joins Jordan Davis, who committed to the Flyers last week.