If you weren't planning on partaking in Red Nose Day until you knew which celebrities were showing up to the televised show, shame on you -- it is a charity event. But if you're curious to know who's supporting it and were planning on tuning in regardless, then we're here to help.

Huge celebrities from all different genres, popular with all different age groups and people are set to appear during the three-hour special. Said celebrities include, but are not necessarily limited to the following: Neil Patrick Harris, Sam Smith, Elizabeth Banks, Julia Roberts, Coldplay, Jennifer Aniston, Julianne Moore, Jodie Foster, Reese Witherspoon, Sienna Miller, John Krasinski, Paul Rudd, Olivia Wilde, Eddie Redmayne, Benedict Cumberbatch, Sir Ian McKellen, Orlando Bloom, Leslie Mann, January Jones, Naomi Campbell, Anna Camp, Jeanne Tripplehorn, Yvette Nicole Brown, Retta, Natalie Morales and Danny Pudi.

Sorry, One Direction fans -- we know the band is notoriously involved in the charity (at least its UK iteration), but they won't be part of the US branch. Simon Cowell, however, will be. Game of Thrones cast members Kit Harington, Peter Dinklage, Nikolaj Coster-Waldau, Emilia Clarke, Iwan Rheon, Thomas Brodie-Sangster, Mark Addy, John Bradley, Rose Leslie, Alfie Allen and Charlotte Hope are also said to make an appearance along with Orange Is the New Black actors Dascha Polanco, Samira Wiley, Yael Stone, Selenis Leyva, Lea DeLaria, Adrienne C. Moore and Jackie Cruz.

In case you were wondering, Red Nose Day has managed to raise over $1 billion over the past 30 years in the UK. The television special will reportedly feature sketch comedy, Funny or Die videos, musical performances and short clips highlighting the charity's work.

Red Nose Day is set to air on May 21 from 8PM to 11PM ET on NBC. Until then, you can check out the full list of celebrities said to appear on the show over at Broadway World.