Let’s look at one of the most important days in anyone’s life: their birthdays. Many people feel that having their own birthday is one of the most significant events in their life. When growing up, they are used to receiving a lot of presents, compliments, and attention from people, because they are considered as cute and lovely kids.
But as you have to face a new world when you are getting older and growing up to be an adult. However, the 21st birthday is such a big deal, because you are already beginning adulthood and you will be able to make your own decisions and to have your own money to spend.
Therefore the 21st birthday is worth celebrating, decide to go out and celebrate their 21st birthday with friends and family or by yourself. Celebrating on social media too is a great way to celebrate.
So are you looking for some best birthday captions? Whatever 21st birthday captions it is you want for your social media post, rest assured you can find them all here.
Related: 22nd Birthday Captions
Celebrating my 21st birthday today. 🎂 Also celebrating my newfound independence as I begin to discover how to transfer my dreams into reality 👁🏼 🍰 Happy birthday to me.
Happy birthday to ME! I’m officially 21. LET’S GO 🎉❤️ I’m so excited.
Can’t believe I’m officially 21 today 🎉 I do not move into a new decade without a big celebration. I have a lot to celebrate, all the wonderful, kind, lovely friends I’ve made throughout these years.
Happy 21st to me and my best year yet 😎💕Can’t believe I’m 21 today. 🎉 👯*
Yes, I’m turning 21 today. Thank you for all the well wishes and happy birthday messages.
Happy Birthday. May I continue to be blessed. After all, I deserve it.
HAPPY BIRTHDAY TO ME!!! 🎂🎈🎉👄 Hey 21, how does it feel? Here’s to the good ones. 🍾🎉
Today I celebrate my 21st #birthday. It’s been an amazing journey getting here. Happy birthday to me.
Happy Birthday to ME! I just turned 21! I’m super excited and happy for myself. May all my wishes come true.
Hey birthday! Didn’t think I’d see you again for another year. 😳 But here you are with a whole new outlook—a whole new year ahead! Let’s make it the best yet. Happy birthday to me.
It’s not where you’ve been, it’s where you are now and I am so thankful I can say I have only seen my future bright. Happy 21st to me!
For Your Friend
Cheers to my best friend turning 21. You are the most incredible person I know and I’m so proud of you, DARLING! 🥂
To My Dear Friend, Congrats on your 21st. Hope it’s a year you always remember, HAPPY BIRTHDAY. 🎈🎉
Happy 21st birthday, buddy! Here’s to you, here’s to 21 years. Can’t want to celebrate a whole lot of birthdays ahead. 💗
Happy birthday to my dear friend and the smartest person I know—you’re a gem. Love you big.
Happy 21st birthday to the dazzling lady that makes our world a prettier place. Love you loads. 💗
So proud of my amazing 💛💙friend. Celebrating her 21st birthday with her and I’m loving it!
We’re celebrating my bestie turning 21! She doesn’t look a day older 😂 So proud of this one, we’ve been besties since childhood, heart you big.
Rich, buttery, and broiled to perfection! Happy 21st to my best friend, you’re a little over the top but I admire your personality. Happy birthday, dearest.
🎉Congratulations to my man on this incredible milestone. Dreams are always one birthday away. Happy birthday, guy. #HappyBirthday.
Happy 21st birthday, dear bestie. You’re an angel on earth. I love you!
Happy birthday to my partner in crime and my soul sister from another mother, Love you big. 🎂🎈🍂
Happy birthday, friend!!! Here’s to turning 21 and seeing what the next year will bring😎
For Your Boyfriend
When you’re so lucky to be able to celebrate your boyfriend’s birthday together with him, It’s just so exciting. Happy birthday, sweetheart. 🌅 😍
I love everything about you! I love that you always make me laugh. 🤣 Happy 21st birthday, babe. I promise to show you how much you mean to me every day.💗
Shout-out to my man, who I’m so proud to call my best friend, my partner in crime, and the love of my life. Happy birthday, dear, love you so much.
Happy birthday, love. I’m so excited to celebrate with you today and I hope we get to celebrate many birthdays together. 💙👨🏼👨
Happy 21st birthday to the man of my dreams! It’s his birthday today. I can’t believe that my dude is now a young man! I love you, buddy. 🥂🎉
Happy 21st birthday to my best friend and boyfriend 😘 I couldn’t be more proud of the man you are today and will continue to become. I love you more than words can explain.
🙏 21 years ago my favorite person was born. I love you and I’m so grateful for every single day we get to spend together. Thank you for being my best friend, my home, my safe haven, and my boyfriend.
Happy Birthday to my favorite person in the world! I love you, and I’m so excited to celebrate your future successes with you! 🎉 😘
For Your Girlfriend
Happy 21st birthday to my partner-in-crime! I love being the crazy one with you—thanks for making my life fantastically unpredictable. 🥂🤠☮️
Happy birthday to the most amazing, loving, caring and beautiful girlfriend in the world… May God bless you with everything you’ve wished for!! I love you so much! ❤️
About to celebrate a year of wonderful pleasures with my girlfriend. 💕 Happy Birthday, sweetie, have a wonderful day. #birthdaygirl.
Sweetheart, you’ve made it to your 21st birthday and I couldn’t be more proud of how far you have come. I love you more than anything else. 🎉🎂🎈
Happy birthday, my angel. I appreciate you more than you will ever know. All my love, forever and always. 💜
Happy Birthday to my girlfriend. I’m so happy that I found you and this is only just the beginning of our relationship. I love you so much.
Happy Birthday to the love of my life. I love you dear and wish you the best in life. 💜
For Your Son
So proud to say that my son turned 21 today. Happy birthday. Love you buddy and have a great day. ❤️
Taking a moment to celebrate my boy’s 21st birthday. Love you dearly and wish you the best in life. Happy birthday, dear. 🍾🎉 #blessed.
Happy 21st birthday, sweetheart! I hope you’re having an unforgettable day. Love you, dear son. ❤️
My amazing son is 21 today. Happy birthday to my big, wonderful boy who always lights up my life when he’s around. #HappyBirthday
Happy Birthday to my darling baby boy – who always loves and supports me, without judgment, unconditionally. I love him back with all my heart 💜, Happy 21st birthday.
Happy 21st Birthday, ❤️! Hope this next decade is the best one yet! ☺️ Love you and wish you the best in this new year of yours.
So proud to toast my baby boy and look forward to all of the memories we have yet to make. Love you, Happy birthday to you.
For Your Daughter
Happy 21st birthday to my favorite daughter. Wishing you many more years of adventures, love, happiness, and plenty of laughter. 😉
I can’t believe my baby girl is 21! As our little pumpkin grows up, my heart just keeps expanding. We love you! Xoxo.
Happy 21st Birthday, baby girl! Here’s to many more birthdays, love you big. 🎂🍾
Happy 21st Birthday to our beautiful girl on the most magical day of the year. We are so lucky to have you! 💛
So blessed to see my daughter turn 21. May her life be filled with magic, wonder, and joy always. Happy birthday, dear.
🎂Happy 21st, to my little girl. I hope all your dreams come true in this new year. Love you forever and always. 💕
Happy 21st birthday to my baby girl. I can’t believe you’re all grown up and about to experience life as a young adult. To me, you will always be my baby girl, but no matter what, you will always be perfect in my eyes.
For Your Brother
Happy, happy birthday to my favorite little brother!! Can’t believe you’re 21. 😊 Happy sweet 21st Bday man! Wish you much happiness!
Cheers to you, my dear brother. Before you were born, I didn’t understand the impact family would have on my life. Happy 21st! I love you! #21
Happy 21st birthday to my sweet brother! You’re pretty much the most awesome human being I know, well maybe next to me😜.
Happy 21st birthday, dear. 🎉 We love you brother and are so thankful for the incredible man you’ve become! #happybirthday.
Happy birthday to my brother—there’s no one who brings more joy and fun to every gathering. You always make me laugh.
Happy Birthday big brother ! Can’t tell you how proud I am to have you as my big brother . #HBDD.
It’s his birthday today! I love you, Lil bro. Don’t worry about a thing because God is with u. What an amazing day we’re in. Make this one awesome and enjoy it to the fullest.
For Your Sister
Celebrating my beautiful sister’s 21st birthday! Love you to the moon and back. Happy birthday.
Happy 21st birthday to my little sister. 🎉 Wish you all the best.
To my sister, who’s not afraid to take risks and follow her dreams. I admire you so much and am so happy that you found yourself even through all the mistakes you’ve made on your journey. Happy Birthday 🎉
That moment when someone turns 21 and you realize what a year it has been. Happy birthday darling sister. 🎂
To my sister, the woman who made a bright path in the world despite some very dark beginnings. Here’s to you on your special day here on planet earth. Happy birthday! 🥂
Happy 21st birthday, dear! I love you and wish you the best for your future!
🎉Happy 21st birthday to one of the most beautiful people that I ever met! Happy Birthday my dear sister! I love you!
For Your Niece
Happy 21st birthday to my beautiful niece, we’re going to have a good time on your special day, and looking forward to the next year!
To my lovely niece upon her 21 st birthday, may you have the best year ever – cheers to a lifetime of celebrations!
I’m so excited to celebrate this beautiful girl turning 21! I’m so proud of you, and I know that your future is bright. #happybirthday #niece.
A big milestone in the journey of life. Happy Birthday to the most amazing niece in the world!!! #21 #somuchlove.
Wishing the best to my beautiful niece on her 21st birthday. I love you and am proud of you for all that you have achieved. We are so lucky to have you in our lives and can’t wait to see what life has in store for you.
Happy 21st birthday to my amazing niece, you are filled with so much joy and light. I love you to infinity and beyond.
As my #niece turns 21 today, I want to say happy birthday and that I hope you never lose your sense of wonder!
For Your Nephew
Can’t believe my nephew’s 21 today! So proud to see you become such a man. Happy 21st birthday. 🎉🎂
Can’t believe my nephew is 21! 🎉 Wishing you a sweet 21st Birthday to celebrate the next big chapter in your life.
Happy 21st birthday to my sweet nephew! I am so proud of you and your accomplishments. ❤️
Happy 21st Birthday! You have completed so many years 🎉 I love you with all our hearts and I wish there are endless more to come. Cheers to your bright future and thank you for being there.
Happy Birthday, sweetheart! I am so proud of you big guy. You make me happy every day and I love you more than words can say. I hope you have the best birthday possible and enjoy all your celebration with friends and family.
I can’t believe my nephew is 21 years old! Here’s to an amazing year. I love you and am so proud!
❤️Happy 21st birthday, nephew …wishing you a life full of adventures and amazing memories!
For Your Cousin
Cheers to my favorite cousin celebrating her 21st birthday today. Happy birthday, dear.
Happy birthday to my cousin who loves to make people feel great! Hope you have a great one.
Happy Birthday, cousin! I hope that the next year will be filled with tons of opportunity, happiness, and success.
It’s your 21st! So many years in the making. Cheers to your future and every golden year to come. Happy birthday, cousin.
It’s a great time to be 21. Here’s to all the wonderful years ahead! let’s do this 21. 🍾🎉
Happy 21st birthday cousin! Party hard and enjoy yourself.
Congratulations cousin on turning 21! I wish you the best in life.🍾 #21today.
Today is my cousin’s 21 st birthday. He’s seen a lot, he’s done a lot, and he’s proven himself as kind and mature enough to claim the title “adult.” Love you, dear.
Celebrating the most handsome cousin in life on his 21st birthday. Cheers 🎂 to a lifetime of adventures
Enjoying my cousin’s 21st birthday and feeling on top of the world! Happy birthday, cousin. #HappyBirthday21
For Your Sister-In-Law
What an adventurous, freethinking soul my sister-in-law is. Happy 21st birthday to her, I love her big.
Happy 21st birthday to the kindest, most beautiful sister-in-law anyone could have! Wish you the best.
A big happy 21st to my darling sister-in-law! Way to go sweet girl, heart you big. 😇🎂
My dearest sister-in-law, 🖤 I hope this day is everything you dreamed of and more. Happy 21st birthday! 🎉
Things are about to get Epic! Today we’re celebrating 21 with the best person in the world – my sister-in-law. I will treasure these memories forever.
🍾🎉 Happy birthday to my siss-in-law and all the adventures we’ve shared so far. Here’s to many more! Love you. #SisterinLaw!
Happy 21st, my little sister-in-law! I can’t wait to see how you grow this year. 💃
For Your Brother-In-Law
21 years old and living the dream! Happy birthday to my brother-in-law, love you, dear.
Happy 21st to the best brother-in-law a girl could ever ask for. You are always full of fun and adventure, and I am so very lucky to call you my family. 🎊🎉👪 #honey.
You’ve got a lot of people who love you so much. We are proud to call you family. Happy 21st birthday, love you.
To my favorite little brother-in-law on your big day, I hope it flows the way you want. 😜🎉 Happy birthday. #birthdayboy.
My brother-in-law just turned 21! happy birthday to my dearest brother. 😘
You’re not just getting older… You’re getting better. Happy birthday, brother. ☺️🍾
Happy 21st birthday, sweet brother-in-law! Let’s keep making memories together! Love you lots!
For Your Boss’s Son
Cheers to the best boss’s son ever. Happy 21st birthday I wish you many more birthdays! 😇_ happy birthday
Celebrating my honey on his very special 21st birthday 🥂 Wish you the best in life.
HAPPY 21st birthday baby boo! This day was always gonna be special no matter what … 💖 love youuuu. ❤️
Here’s to you, sweetheart. Happy 21st birthday and all of our best for the future.
Happy Birthday, son! I’m so excited to see what you accomplish next year 😃
Happy 21st Birthday to my boss’s son, I couldn’t be more proud of you.
Can’t believe he’s 21 🎂 never a dull moment being part of this awesome son of my boss.
Happy 21st birthday to my boss’s son. 🎉 We hope you have an incredible day, surrounded by family and friends you love.
For Your Boss’s Daughter
To our princess on her 21st birthday, you’ve grown up so fast! Happy birthday. ❤️
Happy birthday, SWEETHEART! It’s been an amazing year watching you grow into such a powerful young woman. It makes me so proud of you and I can’t wait to see what this year has in store for you.
🍾🎂Cheers to turning 21. Cheers to exploring all the beauty that this world has to offer. Cheers to oh so much excitement for what’s in store. 👯👩
Celebrating a milestone birthday with you is the best way to begin this new decade. Cheers to more years to come. ♥️ #HappyBirthday.
May today be as beautiful and sparkly as you are. Happy birthday, darling. 🎉 #happybirthday.
Happy birthday to my little sweetheart. 🎂 celebrating my boss’s daughter’s 21st birthday.
Happy birthday to the most beautiful and cool boss’s daughter I have met. We are so proud of you for being so young and with your determination, achieving all that you have. Enjoy your day celebrating yourself because only you deserve it.
For Your Friend’s Child
Happy 21st my beautiful friend’s daughter. I can’t imagine my friend’s life without you. I’m so proud of the person you are, and who you’re going to be. May you have more days full of parties, adventures and love.
Happy 21st birthday to my best friend child. May your dream come true. Thank you for being born because we cannot have any more good times without you gracing the planet with your beautiful spirit.
21 is always going to be your best year. Happy birthday baby! Love you, dear. 🎈
🎂🎂🎉Wishing a Happy 21st Birthday to this guy, who makes me laugh so hard. Love you big.
One for 21…I just want you to know I love you. And happy birthday, dearie. #happybirthday
I don’t know what the future holds for you – but I know this much: right now I’m feeling happy and grateful. thank you for being a wonderful part of our lives and for making my friend a happy mother.
One heck of a sweet 21st birthday for one heck of a sweet girl. Happy birthday, sweetheart.
Happy birthday, darling. 🎉💗. Hope your day is filled with smiles, laughter and lip-smacking food. ☺✨
My friend’s child has long been one of my favorite human beings on the planet. I love you. ☺️
Happy 21st Birthday to our Queen Bee, the best daughter any mother could ever have. We are counting down the days until we can all get back and celebrate you! 🕯🎉