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.
24 products
Owl Reading Book Card for Book Lovers Students Teachers Cute Wise Owl Librarian Readers Glasses Novel Reading Library Thank You Birthday
From £6.49
4 options
Mystical Moon Moth Card Celestial Lunar Birthday Stationary Art Purple Tarot Goth Goblincore Whimsigoth Cottagecore Witchcore Pagan Witchy
From £6.49
4 options
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
4 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
2 options
Eco-friendly • FSC-certified • Plants a tree with every order
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.