A greeting card is an illustrated, folded card featuring an expression of friendship or other sentiment. Although greeting cards are usually given on special occasions such as birthdays, Christmas or other holidays, they are also sent to express thanks or other care. Greeting cards, usually packaged with an envelope, come in a variety of styles, are manufactured as well as hand-made by hundreds of companies big and small. These days, greeting cards with die-cuts or glued on decorations may cost up to five dollars each.

Hallmark Cards and American Greetings are the largest producers of greeting cards in the world. In the United Kingdom, it is estimated that one billion pounds are spent on greeting cards every year, with the average person sending 55 cards per year.

In the United States, many adults traditionally mail Christmas cards to their friends and relatives in December. Many service businesses also send cards to their customers in this season, usually with a universally acceptable non-religious message such as "happy holidays" or "seasons's greetings".