The teenager, from Bradford, got into difficulty just before 8pm on Friday evening while swimming in the River Wharfe.
A police community support officer who was first on the scene gave the man CPR but he was pronounced dead.
Police, paramedics, mountain rescue volunteers and the fire service all attended the incident.
The teenager has not yet been identified.
On the same day, two young women rescued a small child who had drifted downstream in the Wharfe at Burnsall and was struggling to stay afloat.
Posting on Facebook, witness Donna Beveridge said the boy was part of a large family group who had lost sight of him and that his father, who could not swim, claimed he could not move to reach his son because the cold water was hurting his feet.
She wrote: "If you as a parent can’t swim, please think twice about taking your small children to rivers. As what we saw today at Burnsall was horrific! Well done Kelise and Rebecca for saving the little boy from drowning, whilst the father couldn’t even move in three inches of water because it was hurting his feet!
"The dad literally couldn’t stand up, it was awful. No thanks from the parents or large family he was with. An old man came and gave the girls £20 for being heroes."