26 Funny Instagram Captions For Your Sister's Birthday That'll Make Her Smile

For as long as you can remember, your sister has been your best friend. She's been the one you go to when you need to eat some ice cream and talk about your feelings, and the person in your life who's always down for an adventure. You know that at any moment of the day or night, you could text her and say, "Hey, I have an idea," and she'd be all in. She'd be at your apartment or college dorm room with a cooler full of snacks and an "anything is possible," kind of attitude. She'd make you laugh over the inside jokes you have together, and cringe at the embarrassing moments from over the years, too. So, I don't think it's far-fetched to say this: you need some funny Instagram captions for your sister's birthday that'll make her laugh and smile so big.

Let's take a walk down Memory Lane, shall we? Every year has come with its own hilarious moments that you wouldn't trade for the world. For example, when you and your sister were little, you may have chased after the ice cream truck and ordered the popsicles that were shaped like SpongeBob SquarePants. You might have played hopscotch in your driveway and baseball in your backyard. Every once in a while, you may have begged your parents to go to the skatepark, where your sister taught you all kinds of tricks, and cheered you on when you got to the top of the big ramps.

Afterwards, you may have celebrated with another popsicle and a quality chill session on the couch. You watched movies like The Little Mermaid and The Cheetah Girls, and sang along to all the songs. Nowadays, not much has changed, and you'll send each other memes from those iconic films.

But, let's get back to what you're really here for — aka, funny captions for your sister's birthday. You want to make her smile, laugh, and feel every amazing emotion in between. Don't stress, because I think these 26 captions will do the trick.


1. "I was told there would be cake."

2. "Hope your birthday is a piece of cake."

3. "Your birthday is becoming a serious fire hazard."

4. "Wishing you a day as unforgettable as I am."

5. "Too glam to give a damn."

6. "You don't get older, you level up."

7. "Move over, coffee, my sister's birthday is for champagne."

8. "Great news! I didn't need Facebook to remind me it's your birthday."

9. "I forgive you for being younger than me."

10. "Hey shawty, it's sherbert day."

11. "You've been sassy since birth."

12. "Thanks for joining in on my weirdness."

13. "On this day, a queen was born."

14. "I'm sending your selfie to NASA, because you're a star."

15. "It's my sister's birthday and that's the tea."

16. "I know this is cheesy, but I hope you have a really gouda birthday."

17. "Free cake! I mean, happy birthday."

18. "You're the 'she' to my 'nanigans.'"

19. "Here's to another year of chicken nuggets and French fries."

20. "She's not old. She's vintage."

21. "Doughnut crush my sister's vibes on her birthday."

22. "I wonder what's going to happen next."


23. "The one where it's your birthday."

24. "You'll always be my best-tea."

25. "Turns out, I like you more than I originally planned."

26. "All she does is birthday, birthday, birthday."

Did you find a few captions that you like? Sweet, then the only other things you need for your sister's birthday are: a cake, a bunch of glitter, and a gift that's perfect for a millennial. That could be a to-go coffee mug that keeps her brew perfectly hot or cold, or a game from the '90s that reminds her of your childhood together. Personally, I'd pick up a colorful Polaroid camera at the store and wrap it up, so she can create some new #content for her 'Gram. Once you check those items off the list, though, you're ready to celebrate.