An alphabet song is any of various songs used to teach children an alphabet, used in kindergartens, pre-schools and homes around the world. Alphabet songs typically follow the alphabetic principle (though the phonics method offers variants). In languages such as English with morphophonemic variation, an alphabet song usually chooses a particular pronunciation for each letter in the alphabet (i.e. "cake" is /ˈkeɪk/, not [ˈkaːkɛ]) and also typically for some words in the song.

"The A.B.C." ( /ˌeɪˌbiːˈsiː/) or "A.B.C's" ( /ˌeɪˌbiːˈsiːz/) is one of the best-known English language alphabet songs, and perhaps the one most frequently referred to as "the alphabet song", especially in the United States.

The song was first copyrighted in 1835 by the Boston-based music publisher Charles Bradlee, and given the title "The A.B.C., a German air with variations for the flute with an easy accompaniment for the piano forte". The musical arrangement was attributed to Louis Le Maire (sometimes Lemaire), an 18th century composer. This was "Entered according to act of Congress, in the year 1835, by C. Bradlee, in the clerk's office of the District Court of Massachusetts", according to the Newberry Library, which also says, "The theme is that used by Mozart for his piano variations, Ah, vous dirai-je, maman." This tune is more commonly recognizable as "Twinkle, Twinkle, Little Star".