Pinochle (English: /ˈpiːnʌkəl/), also called pinocle or penuchle, is a trick-taking ace–ten card game, typically for two to four players and played with a 48-card deck. It is derived from the card game bezique; players score points by trick-taking and also by forming combinations of characters into melds. It is thus considered part of a "trick-and-meld" category which also includes the game belote. Each hand is played in three phases: bidding, melds, and tricks. The standard game today is called "partnership auction pinochle".

Pinochle is thought to have two possible origins. One is that it is a cousin of Binokel, with both games evolving from the game of bezique.^{[verification needed]} A second alternative is that pinochle actually developed from the Swiss and, later, South German game of Binocle or Binokel, which in turn is a descendant of bezique.

The word pinochle has several different potential derivations. It may come from the French word binocle literally meaning "two eyes", or "eyeglasses" or "binoculars", and was a reference to the mythical notion that the German game of Binocle was invented with a special deck where the Queen of Spades and Jack of Diamonds were pictured in side profile with just one eye each. There are also suggestions that the word pinochle comes from bis (until) and Knöchel (knuckle) because originally the game ended when a player rapped their knuckles on the table. The term may also be related to the French word binage for the combination of cards called "binocle". This latter pronunciation of the game was adopted by German speakers.

German immigrants brought the game of Binokel to America in the latter quarter of the 19th century, where it was mispronounced and misspelled "pinochle." Pinochle was the favorite card game of American Jewish and Irish immigrants, while Skat was the preferred game of a majority of German immigrants. Auction Pinochle for three players has some similarities with the German game Skat, although the bidding is more similar to that of bid whist.

During the few months when the USA was involved in World War I, the city of Syracuse, New York, outlawed the playing of pinochle in a gesture of anti-German sentiment. It was also temporarily banned in some other US cities as a result of its German heritage, but has since regained popularity.

A pinochle deck consists of two copies of each of the 9, 10, jack, queen, king, and ace cards of all four suits, for 48 cards per deck. Aces are always considered high. Pinochle follows a nonstandard card ordering. The complete ordering from highest to lowest is A, 10, K, Q, J, 9. The game can also be played using standard ranking with a simple change to scoring.

Originally, the deck had to be composed by combining two poker, piquet or euchre decks and removing unneeded cards (a piquet deck does not have the 2–6, making it easier to modify, and a euchre deck is exactly half a pinochle deck), but with the game's popularity in the United States in the early 1900s, a single boxed deck with the necessary cards was marketed, and these specialized pinochle decks are now widely available in similar styles to common 52-card counterparts. Variants of pinochle can be played with five, six, eight or more players. These larger variations can combine two pinochle decks called a "double deck". The double deck can also be used when playing with four players; hand sizes, average scores and minimum bids are doubled.

The game is played with a deck of 48 cards and four players; one player is the dealer.