The 40-year-old German model donned a sparkling top hat for her special day and posted a photo of herself and guests posing with hat-shaped cakes on Twitter, reported Daily Star.
All the revellers, including fellow model and reality TV star Yolanda Foster, were wearing hats.
Klum also thanked her fans and friends for "all the wishes, flowers, balloons and gifts".
"Fun day. Thank you," she posted.