The charity show’s hosts are Jason Manford, Mel Giedroyc, Alex Scott, Ade Adepitan and Chris Ramsey.
Lewis Capaldi, Graham Norton, Joe Wicks, Bradley Walsh and Diversity are among the stars taking part in this year’s Children in Need show.
The annual BBC One charity night is raising funds for children and young people across the UK.
Last year’s live show raised £39m.
This year, the celebrity fundraising efforts include Wicks walking a 30-mile ultra-marathon, aiming to finish in 10 hours to join the evening’s show in Salford, Greater Manchester.
“I wanted to do as much as I could for the charity again this year, especially given how hard things are for so many children and young people in the UK right now,” he said.
Friday’s three-hour programme is hosted by Ade Adepitan, Mel Giedroyc, Chris Ramsey, Alex Scott and Jason Manford.
Manford, who is co-presenting the annual event for the first time, said: “Being from an underprivileged background, to help a charity that helps those children, means a lot to me.”
Giedroyc highlighted “so many children facing the very real crisis of poverty this winter”, and Adepitan said it would be “a really emotional night with a lot of powerful stories”.
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The show includes special editions of Blankety Blank, The Repair Shop and The Weakest Link, while Freya Skye, the UK’s Junior Eurovision act, is performing her song live for the first time.
Norton’s Big Red Chair is returning, while the Children in Need Choir are singing Keane’s Somewhere Only We Know.
A companion for Ncuti Gatwa’s new Time Lord on Doctor Who is also being announced.
DJ Scott Mills has already raised more than £1m for this year’s appeal through a gruelling treadmill challenge.
The Radio 2 presenter walked, jogged and ran for 24 hours – even recreating his infamous Strictly Come Dancing “crab dance”.
Other fundraising events to have been broadcast already include Matt Baker’s Rickshaw Relay, along with a team of five young people, all of whom have been supported by Children in Need-funded projects.
DIY SOS built a brand-new home for Leeds-based CiN-funded project Getaway Girls, which saw Nick Knowles and his team work alongside Radio 2 presenters and a group of volunteers.
The BBC Children in Need Appeal Night Show will be on BBC One and iPlayer from 19:00 to 22:00 GMT.