The 28-year-old midfielder could have left Parkhead under the Bosman Ruling and was believed to be attracting interest from English Premiership clubs. However, after missing most of the season with a cruciate knee ligament injury, he has opted to stay in Glasgow.
It is another coup for the new chief executive Allan MacDonald, who has already persuaded another talented Scandinavian, the Swedish striker Henrik Larsson, to commit his future to the club.
"I am delighted to have signed for another three years and it is good that the uncertainty is over," Wieghorst, who was part of the Danish World Cup squad last summer, said. "I have had to write off most of this season but now that I have a few games under my belt I am looking forward to the Cup final and further than that. I decided to stay simply because Celtic is a very good club to be at.
"There was interest from down south but I am convinced that Celtic have a very good future and I want to be part of that," the Dane added. "All the players have been very impressed with Mr MacDonald. It is great to have been able to sort out the contract agreeably."
The Rangers misfit, Marco Negri, has asked for a chance to resurrect his career at Ibrox. The 29-year-old striker was exiled to his Italian homeland earlier this season after an alleged training ground fight with Rangers' captain and his compatriot, Lorenzo Amoruso.
"If I said I was happy to be coming back, it would be a lie," Negri said. "But I am a professional and I have a contract and if they gave me a chance I would play for Rangers. All I want to do is come back and have a proper season."
Negri was off-loaded to the Serie A strugglers, Vicenza, on loan midway through the season. That switch was made with a view to a permanent deal, but that now seems unlikely after Vicenza's relegation.
The striker has never played first-team football for Rangers under the managership of Dick Advocaat. When asked if he believed Negri would turn up for pre-season training, the Dutchman said: "I don't think he will, but maybe he has changed his mind. He has to say he will return because he is still under contract. I won't comment before I know what is going to happen.
"Officially at the end of the year he has to come back, if he doesn't get another club that is," Advocaat added, "but we'll have to wait and see on that in the coming weeks."Reuse content