The British Supercross Championship kick-started the Stadium's busiest month to date on 3rd December and was swiftly followed by the Noise and Confusion Concert featuring Oasis on 10th December and the WRU landmark 125th Anniversary Dinner on the 14th December.
The Blizzard Fun Park, which will last until 5th January, was opened by rugby star Ryan Jones on 15 December, and a series of Vegas style private functions has also filled the Stadium's evenings ever since - the bumper month culminates in the New Year's Eve "Heaven and Hell-themed" celebrations next week.
A grand total of 64,000 revellers partied hard at the Noise and Confusion concert, which also welcomed the Foo Fighters, Razorlight and the Coral the packed out Millennium Stadium.
A Welsh Rugby landmark was celebrated in the Millennium Royale Big Top Pavilion on the pitch area of the Stadium when more than 1,000 people celebrated 125 years of the Welsh Rugby Union.
The dazzling December was revved up by Supercross, the motor sport spectacle that sees 4000 tonnes of dirt cover the massive concrete pitch area of the stadium creating a unique race track, drawing in 12,000 fanatical spectators.
Next a Blizzard was forecast with a massive indoor funfair featuring indoor snow, toboggans, winter rides, roller-coasters and Santa Claus himself - currently welcoming over 1,000 visitors a day and set to break the 20,000 mark before it closes on 5 January.
'The Night it Snowed in Vegas', also at the Vegas themed Millennium Royale Big Top Pavilion, hosts a series of parties throughout December and so far 8,000 party-goers have enjoyed the likes of Elvis and his amazing showgirls, a cheeky spin of the roulette wheel or a dabble on the poker tables.
"December has been an incredible month so far, we have had a record number of events in the stadium in the space of four weeks and isn't over yet," said Millennium Stadium chief executive Paul Sergeant.
"The diversity of the events we've had is fantastic, from Supercross right through to themed dinner parties. We have a genuine open mind about what precisely the Millennium Stadium can be used for and I can honestly say we examine every possible use, no matter how far-fetched it may at first appear, and that policy has paid dividends this month."
Revellers wishing to join the dazzling December party at the Millennium Stadium can celebrate this magnificent month for Wales' iconic, internationally-renowned, multi-event, venue in style on New Year's Eve and bring in 2006 for the price of just £15 in the new Millennium Royale Big Top Pavilion. Tickets are selling fast with 3,000 gone already, remaining tickets are available online at www.millenniumstadium.com or from the ticket hotline 08705 582 582.
"This month's eclectic mix of events really shows how the Millennium Stadium as a building is the ultimate chameleon of venues and with the right preparation and organisation we can stage absolutely anything," added Alex Luff, Venue and Sales manager for Millennium Stadium, who was at the helm in bringing in this amazing schedule of events.
"We had a wicked start to the month and we will have a wicked end with the New Year's Eve 'Heaven and Hell' party, which is estimated to see another 8,000 party-goers become a part of the Millennium Stadium experience."
The Stadium's second busiest month was this November when the Welsh rugby side faced visiting teams from New Zealand, South Africa, Fiji and Australia on back to back weekends in Cardiff.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.