A police spokeswoman said paramedics attended the home in Fisher after the 21-month-old boy was found in the pool.

Police were called to Canberra Hospital about 7.40pm after the boy could not be revived.

Police are investigating the circumstances around his death but a spokeswoman said it was not believed to be suspicious.

Part of that investigation will include examining how the pool was fenced, she said.

Acting Superintendent Matt Craft said a brief would be prepared for the coroner.

"Unfortunately this tragic situation is a reminder that water and children can be a very dangerous combination," he said.