Celebrity·Posted 14 hours ago27 Celebrities Who Turn 40 In 2024, Because, Well, That's Just How Time WorksI truly cannot even fathom Prince Harry, Mark Zuckerberg, and Avril Lavigne being the same age.by Lauren GarafanoBuzzFeed StaffLinkFacebookPinterestTwitterMail One thing about me is that I am extremely fascinated by celebrity birthdays and ages. And just out of plain curiosity, I wondered, which famous people are about to turn 40 in 2024? And just in case you wanted to feel old today, lemme tell you: 1. Katy Perry 2. Prince Harry 3. Avril Lavigne 4. T-Pain 5. Mark Zuckerberg 6. Mandy Moore 7. Kid Cudi 8. Calvin Harris 9. Olivia Wilde 10. Gina Rodriguez 11. Aubrey Plaza 12. Noel Fisher 13. America Ferrera 14. Jack Antonoff 15. Patrick Stump 16. Trevor Noah 17. Kelly Osbourne 18. Scarlett Johansson 19. Fantasia Barrino 20. Paul Dano 21. Lauren London 22. Ashlee Simpson 23. Cecily Strong 24. Christy Carlson Romano 25. Jackson Rathbone 26. Chris Lowell 27. Jena Malone