The invention relates to anti-α2 integrin antibodies and their uses. Humanized antibodies are disclosed that bind to the I domain of α2 integrin and inhibit the interaction of α2β1 integrin with collagen. Also disclosed are therapeutic uses of anti-α2 integrin antibodies in treating α2β1-mediated disorders, including anti-α2 integrin antibodies that bind to α2 integrin without activating platelets.