Nadine Dorries told a rugby league audience how she thoroughly enjoyed England winning the 2003 World Cup – a rugby union tournament.
Ms Dorries confused rugby union and rugby league, commending Jonny Wilkinson's 2003 winning drop-goal for England against Australia.
She said: "I've always quite liked the idea of rugby league.
"My long-standing memory is that 2003 drop-goal."
Ms Dorries added: "We were drinking Bloody Marys at the time. Wow, what a moment that was."
In a later tweet, Ms Dorries acknowledged her mistakes saying: "Like Jason Robinson I may have switched codes in my speech.
Culture Secretary Nadine Dorries made the mistake in a speech in St Helens
Steve Parsons
Ms Dorries confused rugby union and rugby league
Steve Haag
"Both league and union have a rich heritage in the UK. Obviously I've followed rugby league much less in my lifetime, but I'm looking forward to watching England (and all the home nations) in the RL World Cup this autumn."
Chief Executive of the Rugby League World Cup, Jon Dutton, said the Secretary of State had "clearly made a mistake" but added he was thrilled she attended the launch of a report into the event's social impact.
He said: "The sport is 127 years old but needs a tournament like this to have more visibility. We want more people to be educated on what a wonderful sport rugby league is - and also, what a wonderful sport rugby union is.
"We've had a conversation and we look forward to her coming to the tournament."
Billy Vaughan, Vice-Chairman of Portico Vine Rugby League Club in St Helens, where the event took place, said: "I thought it was comical. No detriment to her, somebody writes that speech for her, they just need to do their research. It's a little bit disrespectful to the various codes and there's a big difference in the codes."
The two codes have operated individually since 1895 when rugby league separated from then-amateur rugby union to start a new professional competition.
Key differences between the codes include the number of players on each team: rugby union has 15 on each side while rugby league has 13.
Chief Executive of Rugby Football League, Ralph Rimmer refused to condemn Ms Dorries for her mix-up, opting to thank the Government for its £25m backing.
He said: "I'm not going to dwell on that.
"It's brilliant that she's here and we've had fantastic support from the Government.
"I'm not going to knock the shine off any of that.
"She gets a chance to see us as we really are and good on her for coming up."
