1. Nicole Kidman reminded everyone she's "always been a cat girl":
2. Mark Ruffalo shared an all-too-relatable image of his kitteh Inky:
Happy #InternationalCatDay from me and Inky, who has decided to start earning his keep by helping me read lines for I Know This Much Is True 😻🖊
3. Joseph Gordon-Levitt posted a cute as heck #TBT of himself with a kitteh:
Ok, fine. I'll jump in on this... #InternationalCatDay
4. Luke Evans shared an LOL-worthy GIF...
#InternationalCatDay a big chin scratch to all the those crazy cats around the world today
...and this cute video of his own lil' bb:
5. Thandie Newton posted this doubly adorable photo of her daughter Nico and her fur baby Tiger:
6. Mark Hamill reminded us cats are in fact one with the Force:
Happy #InternationalCatDay! #ForcefulFelines
7. Kylie Minogue posted this cute throwback pic of herself and a kitten:
8. Anthony Hopkins shared this very artistic homage to cats:
Happy #InternationalCatDay
9. Katie Couric showed off her favorite furry grandkitties:
Happy #InternationalCatDay from me and my grandkitties! 😊
10. Ricky Gervais reminded us that EVERY day is actually #InternationalCatDay:
11. Cassandra Peterson (aka Elvira) posed with her PURRfect pal:
My kitty Ash wishes you a purrrfect #InternationalCatDay 🐾
12. Kyle MacLachlan reminisced about his time as a cat-wrangling Mayor on Portlandia:
Happy #InternationalCatDay! Hope your feline friends have a little less catitude than the Mayor’s here 😸
13. Ellen shared this relaxing pic of a cat in not one, but TWO baskets:
14. Author Neil Gaiman posted this pic of himself TRYING to write with his cat in his lap (GOOD LUCK):
Happy International Cat Day. https://t.co/CLgsvhJayb
15. And finally, Stan Lee's estate shared this beautiful image of two iconic legends we lost over the last year:
Throwing it back for #InternationalCatDay in honor of these two legends. #tbt