What to write in a 21st birthday card

Your 21st birthday used to be a major milestone – now, most things become legal at 18, but that doesn’t mean it’s not worth celebrating a whole twenty-one years on Earth! And whether it’s your best mate, son or daughter who’s turning 21, you want to wish them many happy returns in the best way possible, right? Well, we’re here to help with some inspiration for what to write in a 21st birthday card.

And when it comes to that card, don’t settle for some boring generic option. We’ve got a huge range of funny and unique 21st birthday cards, featuring brilliant illustrations and funny quotes – some of which you won’t find anywhere else but right here at thortful. Just to make it even easier, you can even send your card directly with a perfect present for the birthday boy or girl, whether they’d prefer a case of beer or a pretty candle.

Funny 21st birthday card wishes

If you can’t take a laugh when you’re 21 with your whole life ahead of you, then when can you? These funny 21st birthday wishes only poke gentle fun at the birthday boy or girl – pair with one of our funny 21st birthday cards for the full effect.

  1. Enjoy turning 21 – there are no more fun numbers after this one to look forward to. Happy birthday!
  2. Twenty one today! This used to be a proper ‘coming of age’ birthday, but nowadays, it sort of serves as a reminder that it’s still not too late to get your sh*t together. Happy birthday!
  3. I hope you really enjoy your first day of being 21 – because I know for a fact your second day will be spent hungover in bed.
  4. You’re halfway to your forties. If that’s not enough to make you drink, I don’t know what is. Enjoy your birthday!
  5. On this day, you can officially adopt a child, drive an HGV, hire a car, drink booze in the USA, and pilot a helicopter. But before you get busy with all of that, let’s party!
  6. On your 21st birthday, remember to drink sensibly – don’t spill any of it.
  7. You’re only 21 once. Unless you’re 21 twice, in which case you’re 42 and I’ve bought the wrong bloody card.
  8. 21 years and 9 months ago, your parents had sex. Happy birthday!

Heartfelt 21st birthday messages

Keep it sweet, sincere, and genuine as they step further into their twenties with these nice messages to write in a card. Pair with a thoughtful gift like a beautiful bouquet of flowers with a card or a bottle of sparkling wine to really celebrate.

  1. Wishing you a brilliant 21st birthday – have a wonderful day.
  2. Here’s to 21 years of fun times, precious memories, great friends, and a family that love you so very much. Happy 21st birthday!
  3. I can’t believe you’re already 21 – how time flies! Happy birthday.
  4. Remember, life isn’t about finding yourself – it’s about creating yourself. Sending all my love on this special birthday.
  5. Twenty-one this very day! You’re wonderful, it’s true. Party queen extraordinaire, big birthday love to you.
  6. 21 – how did that happen? You’re going to achieve so much in your life, and I can’t wait to watch you do it.
  7. Twenty-one and gorgeous on the inside and the outside. Keep shining for everyone to see.
  8. Congratulations on reaching a major life milestone – you’ve already done some amazing things and made such wonderful memories. I hope the years ahead are filled with even more great times.

Inspirational 21st birthday quotes

Sometimes, someone wiser, smarter, and more famous than you has already said everything you could ever want to say. And they probably said it better. It’s annoying, but at least they’ve done the hard work for you. Here are some thoughtful 21st birthday quotes to write in yourbirthday card.

  1. “Always remember – you are braver than you believe, stronger than you seem, smarter than you think, and more loved than you know.” – Christopher Robin, Pooh’s Grand Adventure
  2. “Don’t just count your years, make your years count.” – George Meredith
  3. “Whatever with the past has gone, the best is always yet to come.” – Lucy Larcom:
  4. “Today you are you! That is truer than true! There is no one alive who is you-er than you!” – Doctor Seuss
  5. “Youth is happy because it has the ability to see beauty. Anyone who keeps the ability to see beauty never grows old.” – Franz Kafka

21st birthday messages for your son

It can be hard to know what to say to your son on a milestone birthday. How do you sum up 21 years of happy memories, mild frustration, pride and love? We’ve got a couple of ideas. Pick up a 21st birthday card for your son and choose any of these sweet suggestions to write inside it.

  1. You make us so proud each and every single day. Happy 21st birthday – we love you so much.
  2. I can’t believe the little baby I held in my arms is turning 21 today. I’m so proud of the kind and capable person you’ve become. Happy birthday!
  3. On this very special birthday, we just want to let you know how deeply proud we are of you, and how much we love you.
  4. I know that the path ahead for you is bright – you deserve every success
  5. Happy birthday – the bank of mum and dad is officially closing its doors! All jokes aside, we’re so proud of you, and we’ll always be here for you no matter what.
  6. You only turn 21 once – I hope this special birthday is more wonderful than you expected, and that your dreams and wishes come true today and every other day.
  7. You know I’ll always be here for you, cheering you on, with a listening ear, a home-cooked meal and a comfy bed. Happy 21st birthday, son – I love you.
  8. You made it through your teenage years, and I know you’re going to achieve amazing things in your twenties. My beloved son, I can’t wait to see what you make of the world.

21st birthday wishes for your daughter

Start your daughter’s birthday off right with a heartfelt message that will make her smile – and if you’re looking for a card to go along with it, we’ve got plenty of sweet 21st birthday cards for her.

  1. You are turning 21, and what a joy you are / This is your day, we’re super proud, our beautiful shining star.
  2. Today you turn 21, and I couldn’t be prouder of the wonderful woman you have become. Happy 21st
  3. Daughter, on this special day, know that I am so incredibly proud of you as you celebrate 21 years on earth.
  4. Wishing you every happiness for this day and all the days you have yet to come.
  5. Happy 21st birthday, daughter. I am so blessed to be your mother, and I am so proud to see how you’ve grown up.
  6. My beloved daughter – it brings me more joy than you know to be wishing you a happy 21st birthday today.
  7. I will always be so very proud of you, and proud to be the mother of such a special daughter.
  8. Daughter, I hope your 21st birthday sparkles with good friends, good times, and magical moments that you’ll always remember.

21st birthday greetings for your brother or sister

No matter how much you and your sibling get a long (or don’t…), their 21st birthday is truly a special occasion which you can celebrate together. Of course, telling them exactly how much you appreciate them can be easier said than done, which is why we’ve come up with a whole range of 21st birthday greetings for you to use.

  1. You’re not just a sibling but my best friend, the past 21 years growing up alongside you have been a blessing. Happy Birthday!
  2. After knowing you for 21 years I think it’s time to fess up… I was the one who told mum that you snuck out of the house that time. My bad but happy 21st.
  3. Happy 21st birthday lil bro, I still remember the exact day that mum and dad brought you home from the hospital. Boy, has a lot changed since then.
  4. Make sure to savour this day and it’s one of the only times you’ll be dad’s favourite, happy 21st
  5. Look at you, a whole 21 years old. As my big sister, you’ll always be an inspiration and I hope to be just as amazing at 21 as you.
  6. Now that you’re 21 does this mean my older sibling responsibilities are no longer necessary? Either way, wishing you the happiest of birthdays and can’t wait to celebrate later!
  7. 21 years ago, you blessed my life by being a forever friend, I shall always cherish all the memories we shared when we were little. Happy 21st Birthday.
  8. All I’m saying is mum and dad better not spend more on your 21st than they did on mine. Oh, and yeah happy 21st!

This should be everything you need to perfectly celebrate their 21st birthday and make sure you get a delighted smile when they read your card, rather than an ‘oh… that’s nice..”

Looking for more birthday-related ideas? Check out our full range of birthday cards. For more inspiration, check out our gift ideas and what to write guides, or more from the thortful blog.