Karuta (かるた; from Portuguese: carta 'card') are Japanese playing cards. Playing cards were introduced to Japan by Portuguese traders during the mid-16th century. The earliest indigenous karuta were made in the town of Miike in Chikugo Province at around the end of the 16th century. The Miike karuta Memorial Hall located in Ōmuta, Fukuoka, is the only municipal museum in Japan dedicated specifically to the history of karuta.

Karuta packs are classified into two groups, those that are descended from Portuguese-suited playing cards and those from e-awase. E-awase originally derived from kai-awase, which was played with shells but were converted to card format during the early 17th century. The basic idea of any e-awase karuta game is to be able to quickly determine which card out of an array of cards is required and then to grab the card before it is grabbed by an opponent. It is often played by children at elementary school and junior high-school level during class, as an educational exercise.

Portuguese-suited playing cards, introduced to Japan by Portuguese sailors during the 16th century nanban trade, are known in Japanese as nanban karuta (南蛮かるた; lit. "playing cards of southern barbarians"). They were used for trick-taking games. They had the four Latin suits of cups, coins, clubs, and swords, each suit having cards for 1 through 9 and three face cards (female knave/maid, knight, and king) for a total of 48 cards per card set. These features were inherited by various Japanese-made derivatives. The Portuguese cards at the time had card backs that were folded around the edges of the cards, a feature that remained standard in most karuta variants from the 17th century to the modern day.

The first kind of Japanese-made playing cards were Tenshō karuta [ja], named after the Tenshō period (1573–1592). They were local imitations of the Portuguese playing cards, featuring the same deck structure and often very similar artwork. The first Tenshō karuta were made in the town of Miike, and are also known as Miike karuta (三池カルタ).

In 1633, the Tokugawa shogunate banned Tenshō karuta, forcing Japanese manufacturers to radically redesign their cards. As a result of Japan's isolationist Sakoku policy, karuta would develop separately from the rest of the world.

In order to evade the proscription of Portuguese-derived cards, makers turned the cards into very abstract designs known as mekuri karuta (めくりかるた; lit. "flip cards"). By the mid-20th century, all mekuri karuta fell into oblivion with the exception of Komatsufuda (小松札; lit. "small pine cards") which is used to play Kakkuri, a game similar to Poch, found in Yafune, Fukui prefecture.

The Unsun karuta [ja] (うんすんカルタ) deck developed in the late 17th century. It has five suits of 15 ranks each for a total of 75 cards. Six of the ranks were face cards of female knave, knight, king, "Un" (うん), "Sun" (すん), and dragon. The Portuguese deck used to have dragons on their aces; the Unsun karuta made the aces and dragons separate cards. The order of the court cards change depending on whether it is the trump suit or not just like in Ombre. The new Guru suit used circular whirls (mitsudomoe) as pips. Unsun karuta is still used in Hitoyoshi, Kumamoto, to play hachinin-meri, a game descended from Guritipau, a relative of Ombre. This game preserves some very archaic features such as inverted ranking for the pip cards in the three round suits. Inverted ranking is a feature found in Madiao, Khanhoo, Tổ tôm, Ganjifa, Tarot, Ombre, and Maw and is believed to have originated in the very earliest card games.

Kabufuda (株札) is another derivative of mekuri karuta but all the suits were made identical. It is used for gambling games such as Oicho-Kabu. They come in decks of 40 cards with designs representing the numbers 1 through 10. There are four cards for each number and the 10 (knave) is the only face card.