The Coast Guard searched the waters off Lillian Street in Kitty Hawk, WVEC reports.
The Coast Guard said the child and mother, who are from New Hampshire, had been walking along the beach when a wave came crashing in and swept the child away. Police said the victim was a 4-year-old boy.
"As parents, this is our worst nightmare, even for those of us who love and have grown up by the ocean," Kitty Hawk Police Chief Joel C. Johnson wrote on social media. "Please join us in thought and prayer for this family as we mourn with them the loss and give thanks for the well-being of our own children.
The Coast Guard said Wednesday night that it had suspended its search about 8:30 p.m.
The Coast Guard launched an MH-60 Jayhawk helicopter crew from Air Station Elizabeth City and a 47-foot Motor Lifeboat crew from Station Oregon Inlet to search for the boy.
The crews arrived on scene and searched along with crews from Kitty Hawk Beach Rescue, Kitty Hawk Fire Dept., Dare County, Corolla Ocean Rescue and others.
"Suspending a search for anyone, let alone a young child, is the most difficult thing a commanding officer in the Coast Guard is called upon to do," said Capt. Bion Stewart, commander, Sector North Carolina. "I can't imagine what the family of this little boy is going through right now."