Cue sports (sometimes written cuesports), also known as billiard sports, are a wide variety of games of skill generally played with a cue stick which is used to strike billiard balls, moving them around a cloth-covered billiards table bounded by rubber cushions.

Historically, the umbrella term was billiards. While that familiar name is still employed by some as a generic label for all such games, the word's usage has splintered into more exclusive competing meanings in various parts of the world. For example, in British and Australian English, "billiards" usually refers exclusively to the game of English billiards, while in American and Canadian English it is sometimes used to refer to a particular game or class of games, or to all cue games in general, depending upon dialect and context.

There are three major subdivisions of games within cue sports:

• Carom billiards, referring to games played on tables without pockets, including among others balkline and straight rail, cushion caroms, three-cushion billiards and artistic billiards
• Pool, generally played on a table with six pockets, including among others eight-ball (the world's most widely played cue sport), nine-ball, straight pool, one-pocket and bank pool.
• Snooker, which while technically a pocket billiards game, is generally classified separately based on its historic divergence from other games, as well as a separate culture and terminology that characterize its play.

More obscurely, there are games that make use of obstacles and targets, and table-top games played with disks instead of balls.

Billiards has a long and rich history stretching from its inception in the 15th century; to the wrapping of the body of Mary, Queen of Scots, in her billiard table cover in 1586; through its many mentions in the works of Shakespeare, including the famous line "let's to billiards" in Antony and Cleopatra (1606–07); and through the many famous enthusiasts of the sport including, Mozart, Louis XIV of France, Marie Antoinette, Immanuel Kant, Napoleon, Abraham Lincoln, Mark Twain, George Washington, French president Jules Grévy, Charles Dickens, George Armstrong Custer, Theodore Roosevelt, Lewis Carroll, W.C. Fields, Babe Ruth, Bob Hope, Jackie Gleason, and many others.