The 33-year-old prince was punched in the head by an unknown assailant, the newspaper reported.
"The prince was attacked, unprovoked. He is doing fine, there were no injuries," said Royal Court press spokesperson Bertil Ternert to the TT news agency.
The incident is reported to have occurred at around 3am on Saturday morning.
As the prince was leaving the Baoli nightclub, where he had spent the evening with his girlfriend Sofia Hellqvist and friends, he was attacked by an unfamiliar man.
According to Aftonbladet the man managed to get a grip of the prince's neck and Hellqvist was forced to intervene to protect her beau.
"Darling, darling," she is reported to have screamed.
There were around ten people around the prince at the time and several became involved in the fight, with further punches thrown, according to Aftonbladet.
According to a witness the prince then promptly left with his friends and headed in the direction of the harbour.
The King and the Queen have been informed of the incident.
According to the Royal Court the attack will not have any significant impact on Prince Carl Philip's schedule.