Towering roller coasters are under construction, the dodgems are being set up and the steps are being swept ready for the arrival of thrill-seeking crowds as the gates open at 5pm today.
The fair boasts more than 150 attractions, including several stomach-churning roller coasters, a ghost train, four fun houses, dodgems and waltzers.
For those with a head for heights, a giant 33-metre observation wheel has been added to the line-up for the first time.
Other new rides include the Top Buzz and Superstar.
Roger Tuby, of International Fun Fairs, said: “The fair is better than ever.
“We are proud to once again present the biggest selection of theme park and fun fair rides to be seen at any Valentine’s event in the UK and one of the largest fairs in the whole of Europe.
“We are looking forward to welcoming families from across the city and beyond for what is a truly spectacular half term experience.”
A Bavarian-style pub with an indoor seating area is also being set up, along with giant games, food and novelty stalls.
A free model show will also be held from 11am to 4pm on Sunday, February 14, at Leeds United’s Billy’s Bar Suite, where visitors will be able to see the rides in miniature form.
The fair was originally held in Leeds city centre from 1992 until 2000 but moved next to Elland Road in 2001.
It is now in its 25th year and runs until Sunday, February 21.
This year it is supporting Martin House Hospice as its chosen charity.
The hospice, near Boston Spa, cares for children and young people with life-limiting illnesses.
Entry to the fair is £1 and parking is free.
Visit www.leedsvalentinesfair.co.uk for details.