The colourful businessman, who founded Saxo Bank and made his fortune by selling his stake in the online trading platform to Chinese carmaker Zhejiang Geely and Finland's Sampo Oyj last year, says he takes inspiration from clubs like Porto.
This week, he spent around 222 million Danish crowns (25.5 million pounds) buying a 23 percent stake in Parken Sport & Entertainment, owners of FC Copenhagen.
Seier Christensen has become a well-known public figure in Denmark, hosting his own TV-show and posting photos from his private yacht in the Mediterranean and from Michelin-starred restaurants around the world.
Eight years ago he and his family moved to a castle in Switzerland, in part, he said, to escape the high tax burden in Denmark.
"Now that I've sold Saxo Bank, I need to find some big things to get involved in. This is one of them," he said of his investment in FC Copenhagen.
His investment firm Seier Capital holds cash and assets worth around 350 million euros (300.7 million pounds), a fortune that mainly came from his sale of Saxo Bank. He has not disclosed his exact net worth.
He says twice European champions Porto, who beat AS Roma on Wednesday to reach the Champions League quarter-finals, provide a good model for Copenhagen.
On the back of "intelligent player transactions", the Portuguese club have been successful economically and on the pitch, reaching the Champions League knockout stages in four of the last five seasons.
"Why shouldn't FC Copenhagen be able to do what FC Porto has done? I don't see any reason why not," he told reporters in Copenhagen on Thursday.
"Looking into the future, participation in Champions League should be the rule rather than the exception," Christensen said of his ambitions for FC Copenhagen.
The club last made it to the Champions League group stage in the 2016-17 season and have never won a major European trophy.
"I still haven't spent all my money from selling Saxo Bank yet, so this is an opportunity," he said when asked about investing in the playing squad.
"I don't want to be caught in some silly race to buy a very expensive team with the risk of losing a lot of money. I'm ready to look at sound investment opportunities, and if that takes further investments then of course I'll look at it," he said.
Since selling his Saxo Bank stake, Seier Christensen has invested in an ice hockey team in Copenhagen, in a blockchain network, and an unsuccessful attempt to bring Formula One to Copenhagen.
(Reporting by Jacob Gronholt-Pedersen; Editing by Toby Davis)
