37 Ways to Say “Happy Birthday, Unbiological Sister”
Having a sister is like having a built-in companion, but if you don't have any biological sisters, an “unbiological” sister can be just as special to you.
An unbiological sister is even closer than a best friend. She's someone you can rely on no matter what you're facing, who will support you, give advice, and listen to your secrets.
Close friendships between women not only provide emotional support, guidance, and companionship but can also improve your health! A study of breast cancer patients found better outcomes in women with larger groups of friends, even if those friends lived far away.
On your soul sister's birthday, it's lovely to take the opportunity to celebrate her and remind her how important she is to you.
Below, we have more than 30 “happy birthday, unbiological sister” messages, plus tips to help you create your own personalized options!
• Thank you for being my one true friend and sister, and for allowing us to do things together instead of competing. I love you! Happy birthday!
• Here's to bigger, better, and brighter years ahead. May your every wish come true this year, and may you only experience happiness and love. Happy birthday, soul-sister!
• BFF means Best Friends Forever, but do you know what SBFD means? It's “Sister but Friend in Disguise.” Happy birthday to my SBFD!
• Warm birthday wishes to a special lady who I'm lucky to consider a sister. You are truly remarkable, and apart from being your soul-sibling, I'm blessed to be your friend too. Happy birthday, girl!
• Cheers to another year around the sun. Happy birthday, sis!
• Happy birthday, soul sister! I'm really proud to be your best friend. I look up to you in everything, and I know you will continue to inspire me. Enjoy your day!
• Friends come and go, but family is forever. We might not be family by blood, but I'm honored to call you my sister! Happy birthday!
• I'm so blessed to have an unbiological sister like you. You are the greatest and deserve all the happiness in the world on your special day. Happy birthday!
• I don't know what I'd do without you in my life. Happy birthday, soul sister!
• Happy birthday to you today, my sweet friend! You're like the sister I never had and you mean more to me than you'll ever know. I'm confident that we'll be friends for life and sisters for eternity. Enjoy your special day — you deserve it!
• Happy birthday to my sister at the soul and a friend close to my heart! I hope your special day this year is everything you want it to be!
• We may not be sisters by birth, but we're sisters at heart and siblings by choice. I couldn't be luckier than to have you in my life, and I wish you the very best in the coming year! Happy birthday!
• On this special day, let me wish you good luck, lots of happiness, and love. In a word, I wish you an amazing life. Happy birthday!
• Happy birthday to that one friend of mine who will always be more like a sister to me! Love you lots, girl!
• Through thick or thin, I can always count on you. That's why I hope you enjoy your special day to the fullest! Happy birthday, [nickname]!
• My dear soul sister and kindred spirit, I'm sending my best wishes your way on your very special day today. We share a bond unlike any other, and I will always be grateful for having someone as spectacular as you in my life. Happy birthday!
• Sister (noun): a person who knows you inside and out. That sounds like you! I'm so grateful to have you in my life. Happy birthday!
• We may not be sisters by birth, but somewhere deep within me, I feel I've known you forever. You're my true sister, FOREVER. Happy birthday!
• A sister may fight with you, taunt you, scowl at you, or trouble you. But at the end of the day, she'll always love you. Happy birthday, my soul sister!
• You are the sister I got to choose. I'm so thankful for your friendship. You deserve the very best, and I hope [age] is fantastic for you! Happy birthday!
• Happy birthday to one soul sister from another! You mean the world to me, and I hope your special day is nothing short of perfection!
• We weren't sisters by birth, but we knew from the start… fate brought us together to be sisters by heart. Sister, I love you so much and hope you have an incredible [age] year! Happy birthday!
• In my heart, you will always be a true sister to me first and foremost, and then a friend second. Our bond has grown so strong that, to me, you are like family. May you have a wonderful birthday today!
• If we can't be biological sisters, at least we can be unbiological sisters for life! Here's to another incredible year! Happy birthday!
• Some friends are exactly that, and some friends are more like family. You're the latter. You're more of a sister than a friend. Happy birthday!
• Sending beautiful birthday wishes to my best friend, who is like family to me. You may not be my sister by blood, but you truly are by heart!
• A special friend I truly adore, in my heart you've earned sister status and so much more! Happy birthday!
• Because of you, I laugh a little harder, cry a little less, and smile a lot more. I hope this year you laugh a little harder, cry a little less, and smile a lot more. Happy birthday, sis!
• What do you wish for a sister-like friend as incredible as you, who is already so amazing and who has accomplished so much? Eternal joy and happiness, I guess! I hope that you always find contentment in everything you do and that the good always far outweighs the bad in life. You deserve every happiness! Have a marvelous birthday!
• It's hard to give up on my dreams when my unbiological sister is my cheerleader. Thanks for all you do, girl! Happy birthday!
• Sending lots of love and wishing you a sweet birthday today, my closest friend and true sister at heart!
• You're my closest friend and a true soul sister indeed! You're the driving force behind the amazing things that I do in life. Happy birthday!
• I've always longed to have someone I can call my sister. That's why I'm so grateful for having you around. Happy birthday!
• To the only one who can read my thoughts and moods without glasses, happy birthday!
• Happy birthday to my soul sister! Even though we're not related by blood, you have loved me more than my own family. Thank you so much. Cheers on your birthday!
• Happy birthday to the best gossip buddy on the planet, my one and only unbiological sister!
• My dear sister from another mister, you are a one-in-a-million find and a priceless diamond. Happy birthday!
How to Craft the Perfect Happy Birthday Message for Your Unbiological Sister
Your unbiological sister is undoubtedly one of the most important people in your life.
Since she means so much to you, a personalized message might be more fitting than a pre-written one for her birthday.
Keep the following tips in mind to help you write:
• Make it personal. Make references to memories, favorites that you share, or dreams she has for the upcoming year. The more personal your message is, the more meaningful it will be for her to read!
• Keep it light. A birthday is a celebratory occasion! You and your unbiological sister have probably been through a lot together, but it's best not to bring down the mood on her special day, so keep your message positive and sweet.
• Don't be afraid to get mushy! While it's good to keep the mood light, that doesn't mean you should entirely avoid emotion. If there's ever a time to share excessively sentimental thoughts and words, it's a special occasion like a birthday! Use your message to emphasize how much she means to you.
• “45 Unbiological Sister Quotes,” Mums Invited[↩][↩][↩][↩][↩][↩]
• “Birthday Wishes For Unbiological Sister: Best Wishes Sayings,” Congratulations Wishes[↩][↩][↩][↩][↩][↩][↩]
• “100 Touching Birthday Wishes for Sisters and Sisters-in-Law,” Good Housekeeping[↩][↩][↩]
• “Happy Birthday Soul Sister Wishes and Quotes,” Top Happy Birthday Wishes[↩][↩][↩][↩]
• “100+ Beautiful Birthday Wishes for Friend like Sister,” Happy Birthday Wisher[↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩]
• “Poem About Friends That Feel Like Sisters, True Sisters,” Family Friend Poems[↩]
Lindsey Desmet
Sisters are special indeed. There’s no bond quite like the one you will have with your sister – she probably knows you better than anyone.
You’ve likely told her most of your secrets and shared some of your life’s most important moments with her. So, when it comes to her birthday, you want to make sure that each and every one she celebrates is just as special as she is.
Your sister is one of your best friends for life, someone you can always rely on, no matter what. She has been alongside you since you were little, through all the best parts of life and worst too.
Let’s take a look at some easy ways to make your sister’s birthday extra special with the perfect message for her card!
Jump To a Section Below
• How To Wish Your Sister a Happy Birthday
• Funny Birthday Wishes for Your Sister
• Sincere Messages To Your Sister On Her Birthday
• Happy Birthday Sister Quotes & Poems
How To Wish Your Sister a Happy Birthday
The more personal the card is, the more heart-warming your sister will find it. Below, you will find some great ways to add the personal touch to your sister’s birthday card:
• If you have a nickname for your sister, address the card using it. She will love the special touch, and will no doubt be reminded of the unbreakable bond that you share with her. Similarly, if your sister has a nickname for you, sign the card with that nickname. It will surely put a bright smile on her face!
• If you have an inside joke or reference, incorporate it into the card. Or, if you have a special memory of the two of you, share it in writing. She’ll treasure your words for years to come.
• Think about what makes your sister special; is it her great sense of humour, her impeccable style or perhaps a very unique and special talent? Whatever it may be, try and write a little something that refers to, or encompasses, everything that makes her special. The message you write in her birthday card will go a long way in making her day more memorable.
• Whatever you write, make sure that it comes from the heart. She will appreciate the special effort that you put into her birthday card, and she will undoubtedly love the sentiment.
We've come up with a few ideas to help you write the perfect birthday card to go with an amazing gift for her. Feel free to take these messages and adapt them into something that you know your sister will absolutely adore.
Funny Birthday Wishes for Your Sister
• The best part about being your sister is having a best friend who is almost as pretty as me. Happy birthday, my darling sister!
• To my sister on her birthday: You’re not old, you’re classic! Happy birthday! Sending you lots of love on your special day.
• I could write over a million poems about your elegance and grace… But Mom always taught us not to tell lies! Happy birthday, my sister!
• My darling sister, at times you were a thorn in my side, a worm in my apple and a pimple on my chin – but, through thick and thin, you have always been my sister. Happy birthday, you spontaneous, beautiful, witty and silly lifelong friend! I love you forever!
• They say that wisdom comes with age, but it looks like you still have a few more years until you get there. Happy birthday, my sweet sister! Enjoy it like only you can!
• There are just some people in life who drive you absolutely crazy, but we still love them. They are called sisters. Happy birthday to my favourite sister! I love you more than words can say.
• You drink way too much, you swear way too much and your morals are quite questionable – you are everything I could ever wish for in a sister and more! Happy birthday! Here’s to another year of making your own rules. I love you!
• Today, we celebrate the birth of Mom and Dad’s second favourite child: you. Happy birthday, my darling sister! I love you so much.
• I love my sister so much… because we are the same size. Now I have double the wardrobe! Happy birthday to my dearest sister. Sending you the best wishes on your special day.
• Your birthday is always special to me because it’s one of the only things I never had to share with you when we were kids! Happy birthday to you, my sister. Enjoy YOUR special day! I love you to the moon and back.
Sincere Messages To Your Sister On Her Birthday
• I have had many friends come into my life and go away again, but my sister has always been by my side. Happy birthday to my best friend. I love you!
• Sisters share every emotion together: joy, laughter, jealously, happiness and anger. This makes us the finest friends of all. Happy birthday, my sister. You mean the world to me!
• To my darling sister – you are the only person in the whole wide world who can turn my tears into smiles. This year, I wish you nothing but happiness, joy and love. Happy birthday!
• I know I’m never alone because I always have you by my side, my sweet sister. Happy, happy birthday to you!
• Wishing you a very happy birthday, my gorgeous sister. Thank you for being my best friend and for always sticking by me. I love you more than words can say.
• On this very special day, I look back on every beautiful memory we share. Here’s to creating many more! Happy birthday, my dearest sister!
• My sister is no ordinary human being. She has the patience of a monk, is beautiful on the outside, but even more so on the inside. Happy, happy birthday to my sister and best friend.
• I am so lucky and eternally grateful to have such a beautiful, precious friendship with my wonderful, sweet, caring and loving sister. Happy birthday to you! I love you so much.
• Fate and luck may have made us sisters, but there’s no one else I would have chosen anyway. I love you so much. Happy birthday!
• My childhood would have been incomplete without a sweet sister like you. We cannot compare our friendship to anything in the entire world, and I will cherish our memories forever. Happy, happy birthday to you, my darling sister!
Happy Birthday Sister Quotes & Poems
If you want to add a little extra inspiration, use one of these quotes, or make up your own!
• "A sister is a gift to the heart, a friend to the spirit, a golden thread to the meaning of life." – Isadora James. Happy birthday to my heart’s gift, my spirit’s friend and my golden thread to the meaning of life! I love you!
• "There is space within sisterhood for likeness and difference, for the subtle differences that challenge and delight; there is space for disappointment and surprise." – Christine Downing. Thank you for sticking by my side through it all. Happy birthday to you, my amazing sister!
• "We’re connected, as women. It’s like a spiderweb. If one part of that web vibrates, if there’s trouble, we all know it, but most of the time we’re just too scared, or selfish, or insecure to help. But if we don’t help each other, who will?" – Sarah Addison Allen. Happy birthday to you, my sister. I will always be here to help. I love you!
• "Never hold resentments for the person who tells you what you need to hear; count them among your truest, most caring, and valuable friends." – Mike Norton. Thank you for being one of my truest, most caring, and most valuable friends. Thank you for being my sister. Happiest of birthdays to you!
• "Sister. She is your mirror, shining back at you with a world of possibilities. She is your witness, who sees you at your worst and best, and loves you anyway. She is your partner in crime, your midnight companion, someone who knows when you are smiling, even in the dark. She is your teacher, your defence attorney, your personal press agent, even your shrink. Some days, she’s the reason you wish you were an only child." – Barbara Alpert. Thank you for being there through it all. Happy birthday, my darling sister! I love you more than words can say!
• "You keep your past by having sisters. As you get older, they’re the only ones who don’t get bored if you talk about your memories." – Deborah Moggach. Here’s to many more memories! Happy birthday to you, my sweetest sister! I love you.
• "Sweet, crazy conversations full of half sentences, daydreams and misunderstandings more thrilling than understanding could ever be." – Toni Morrison. I can’t wait for more crazy conversations and daydreams with you, my sister. Happy birthday!
• "Because angels are sometimes busy elsewhere, god created sisters like you." – Sal Williams. Happy birthday, my sister!
• "A sister can be seen as someone who is both ourselves and very much not ourselves — a special kind of double." – Toni Morrison. Happy birthday to my sister, my special kind of double. I love you always!
• "Sisters annoy, interfere, criticize. Indulge in monumental sulks, in huffs, in snide remarks. Borrow. Break. Monopolize the bathroom. Are always underfoot. But if catastrophe should strike, sisters are there. Defending you against all comers." – Pam Brown. Happy birthday to my great defender! I love you, my sister.
Be inspired by these messages and write a message in your sister’s birthday card that she’ll remember forever! From the funny to the serious, choose whatever suits your relationship best and make her day all the more special.