Emergency services attended Nottingham Road, Somercotes, on Wednesday afternoon after receiving reports that a 23-month-old boy had been found unresponsive in a paddling pool.
He was taken to Royal Derby Hospital but was sadly pronounced dead despite the best efforts of medics.
A spokesperson for Derbyshire Constabulary said: “Our thoughts are with his family at this most difficult of times.
“Officers are continuing their enquiries into the circumstances around the incident on behalf of the coroner.”
A spokesperson for East Midlands Ambulance Service confirmed it was called to the incident.
They said: “We received a call at 1.23pm on June 2 to a commercial address in Somercotes.
“The caller reported a medical emergency.
“We sent two paramedics in fast response cars and a double-crewed ambulance.
“The air ambulance was also in attendance.
"One patient was taken to Royal Derby Hospital via double-crewed ambulance.”