21st Birthday Cards
Mark the special 21st birthday with our unique card collection
A 21st birthday is a lovely excuse to celebrate everything that makes someone special. Choose a card for your son, daughter or friend by thinking about their personality: a little humour for someone who loves a joke, a moonlit sky for a stargazer, or watercolour flowers for someone who enjoys botanical art.
This collection includes hand-picked, age-neutral cards suitable for an adult 21st birthday; these designs do not need a printed number to mark the occasion. Check the individual product details before choosing your favourite. In your message, mention a shared memory, something you admire about them, or a wish for the year ahead. You can make the milestone explicit with a simple “Happy 21st birthday” and then add the words only you could write.
Need words for the card?
Cute Highland Cow Birthday Card Whimsical Scottish Cow Illustration Teal Blue Orange Wildflowers Daisy Animal Lover Nature Happy Mail Cards
From £6.49
4 options
Labrador Birthday Card From the Dog for Doggy Lovers Dog Dad Mum Golden Retriever Lab Cute Party Hat Happy Celebration Pet Sitting Thank You
From £6.49
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Watercolor Highland Cow Greeting Card Summer Landscape Nature Lovers Cow Enthusiasts Scottish Countryside Birthday Thank You Just Because
From £6.49
2 options
Highland Cow Birthday Card Moon Reach for the Stars Galaxy Greeting Cards Iridescent Achieve your Dreams Goals Strength Resilience Dream Big
From £6.49
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Birthday Cake Card Watercolour Painting Elegant Celebration Happy Wishes Slice of Layered Iced Sponge Candle Greeting Card for Friends BFF
From £6.49
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SImple Flower Card Loose Florals Birthday Botanical Note Cards Notelets Pink Abstract Any Occasion Blank Inside Minimalist Get Well Soon
From £6.49
4 options
Stay Magical Mushroom Greeting Card Witchy Vibes Birthday Card For Nature Lovers Eco Mystical Night Sky Design Witchcore Tarot Style Art
From £6.49
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Abstract Cat Card Colourful Watercolour Painting Crazy Cat Lady Lovers Birthday Thank You Pet Sitting Greeting Cards for Mum Wife Sister
From £6.49
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Adulting Birthday Card Funny Fitted Sheet Joke, Growing Older Relatable Humour for Husband Partner Friend Housework Mum Dad Quirky Aging Fun
From £6.49
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Happy Birthday Slice of Cake Card Strawberry Pink Blue Layered Sponge Loose Messy Watercolour Painting Greeting Card for Her Wife Mum BFF
From £6.49
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Mystical Moon Moth Card Celestial Lunar Birthday Stationary Art Purple Tarot Goth Goblincore Whimsigoth Cottagecore Witchcore Pagan Witchy
From £6.49
4 options
Owl Reading Book Card for Book Lovers Students Teachers Cute Wise Owl Librarian Readers Glasses Novel Reading Library Thank You Birthday
From £6.49
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Whimsical Highland Cow Birthday Card Aurora Borealis Moon Stars Galaxy Celestial Night Sky Magical Scene Rainbow Colours Greeting Cards BFF
From £6.49
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Ocean Birthday Card Luxury Watercolour Gold and Teal Waves Abstract Under the Sea Themed Design Eco Friendly Swimming Beach New for 2026
From £6.49
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Mushroom Birthday Card Magic Enchanted Night For Cottagecore Lovers "Have a Magical Birthday" Surreal Toadstool Fungi Pagan Witchy Gift Art
From £6.49
4 options