Tonight, dance music fans will kick off the celebration with an outdoor party in George Square.
A crowd of 14,000 over-18s will be entertained by a packed bill of top DJs including some of the best known names from the dance music world.
Tiesto and Pete Tong will perform alongside Radio 1 DJs Annie Mac, Zane Lowe and Danny Howard, and the whole event will be broadcast live on Radio 1.
All the free tickets for the George Square dance party were snapped up in less than 40 minutes after being released.
A total of 50,000 passes for the main event, in Glasgow Green on Saturday and Sunday - which stars big names including Katy Perry, Coldplay, One Direction and Paolo Nutini - sold out in just 30 minutes.
Jason Carter, Radio 1's head of live music, events and popular music, said organisers always expected there would be a high demand and added: "The event's reputation is such that every year ticket demand is huge, we are not surprised that tickets have gone so quickly."
The George Square party opens today at 5pm, with entrances located on George Street and Cochrane Street.
It is due to finish around 11pm.
Organisers are warning party goers that the over-18s age restriction will be strictly adhered to and people must bring identification with them.
There will be two bars inside the Square and staff will operate a 'Challenge 25' policy. This means that they will ask people who they think look under 25 to provide identification to prove they are over 18.
Food and drink can not be brought into the Square, with the exception of water in a bottle with an unbroken seal.
There will also be food stalls on site.
Access to some essential city hotspots will be blocked this weekend as events in the city centre and George Square get underway.
Both George Square and Glasgow Green have been enclosed with fencing ahead of the musical spectacular to allow tents, stages and bars to be set up for both events.
There will be no access to George Square until 8am on Monday, while Glasgow Green has been blocked off since last Friday and will remain closed until next Friday.
Roads around George Square - including Cochrane Street, George Street, Hanover Street, John Street, Nelson Mandela Place and North and South Fredrick Street - closed this morning and will stay shut 8am on Saturday.
Glasgow City Council is urging people to plan their journeys in advance.
A council spokesman said: "Diversions will be signposted on streets around the events.
"Drivers are advised to consider alternative routes before and during these events."
Motorists will also be banned from streets around Glasgow Green - including Binnie Place, Monteith Row, Monteith Place, parts of Charlotte Street, Greendyke Street and Steel Street - from 1am on Saturday morning until just before midnight on Sunday.
The Clyde walkway will also be closed on Saturday and Sunday.
A BBC spokeswoman said: "Radio 1's Big Weekend requires a lot of planning and manpower. This involves setting up the event's infrastructure, including tents and bars, as well as a number of stages ahead of the event in order to accommodate performances across the weekend.
"The BBC is working closely with Glasgow City Council to minimise disruption to local residents and has held regular liaison meetings with residents to gain an understanding of the issues hosting an event in this location will cause."