Prince Carl Gustav, Duke of Småland (25 August 1782 – 23 March 1783) was a prince of Sweden, being the son of King Gustav III of Sweden and Queen Sophia Magdalena.

The baby was described as strong, healthy and big; Carl Gustav's father was especially fond of him.

In March 1783 the young Prince suddenly took ill, probably from inappropriate food[1] and died when he was little over a half year old.

His father took the death very hard and had never been seen so grief stricken, unable even to attend the little boy's funeral.

Several writers have attributed the change in his personality and activity at least in part to his strong reaction at the death of his second son.