King has been sentenced to 18 months in prison after being found guilty of a nightclub attack on a young woman.
He was unanimously convicted of sexually assaulting a 20-year-old and causing actual bodily harm following a hearing at London's Southwark Crown Court on Thursday.
Wigan have now acted quickly to cut their ties with the player and he will be left without a club after a mandatory notice period has expired.
"It is upsetting to hear that Marlon has got 18 months but I am sure he deserves it," Whelan told Sky Sports News.
"We have to follow the rules and regulations and we have given him 14 days' notice that his contract will be cancelled.
"He is absolutely sacked. We will not tolerate this kind of behaviour and as far as we are concerned he is finished football with Wigan Athletic."
RegretWhelan is bitterly disappointed that King let the Latics down and set a bad example to youngsters who may have looked up to him.
"Right from the start they are told they are representing Wigan on and off the field and especially off the field," Whelan explained.
"Young people look up to professional footballers and we have to set the standards."
Whelan admits he now looks back with regret on the day he brought King to Wigan from Watford in January 2008.
"I do personally regret the day. I always thought his heart and soul wasn't in being a professional footballer," Whelan reflected.
"I sat him down at the start of the season and told him this was his last chance and it is very disappointing.
"I don't want Wigan's name dragged into this. Marlon was out on loan at Hull, and I don't blame them either, it is just disappointing that a footballer can sink to those levels."
Whelan now doubts whether King will be given another opportunity to play football at a professional standard.
"It would be very difficult for any club to stick their neck out and sign Marlon. I can't see him coming back," he concluded.
StatementA statement on Wigan's official website later confirmed King's departure, saying: "Following the news that Marlon King has been sentenced to 18 months imprisonment, Wigan Athletic wishes to confirm that the player's contract will be terminated with due notice, in accordance with the terms and conditions of his contract and the Premier League rules.
"The incident took place while the player was on-loan at Hull City but ultimately still as a Wigan Athletic player and a representative of the club.
"Although the club was aware of the incident at the time, it was not aware of the severity, and therefore believes that the sentence received is justified by the player's actions."