Bolero is a genre of song which originated in eastern Cuba in the late 19th century as part of the trova tradition. Unrelated to the older Spanish dance of the same name, bolero is characterized by sophisticated lyrics dealing with love. It has been called the "quintessential Latin American romantic song of the twentieth century".

Unlike the simpler, thematically diverse canción, bolero did not stem directly from the European lyrical tradition, which included Italian opera and canzone, popular in urban centers like Havana at the time. Instead, it was born as a form of romantic folk poetry cultivated by a new breed of troubadour from Santiago de Cuba, the trovadores. Pepe Sánchez is considered the father of this movement and the author of the first bolero, "Tristezas", written in 1883. Originally, boleros were sung by individual trovadores while playing guitar. Over time, it became common for trovadores to play in groups as dúos, tríos, cuartetos, etc. Thanks to the Trío Matamoros and, later, Trío Los Panchos, bolero achieved widespread popularity in Latin America, the United States and Spain. At the same time, Havana had become a fertile ground where bolero composers met to create compositions and improvise new tunes; it was the so-called filin movement, which derived its name from the English word "feeling". Many of the genre's most enduring pieces were written then and popularized in radio and cabaret performances by singers such as Olga Guillot and Elena Burke, backed by orchestras and big bands.

Boleros are generally in 4/4 time and, musically, compositions and arrangements might take a variety of forms. This flexibility has enabled boleros to feature in the repertoire of Cuban son and rumba ensembles, as well as Spanish copla and flamenco singers, since the early 20th century. Occasionally, boleros have been merged with other forms to yield new subgenres, such as the bolero-son, popular in the 1930s and 1940s, and the bolero-cha, popular in the 1950s. In the United States, the rhumba ballroom dance emerged as an adaptation of the bolero-son in the 1930s. Boleros can also be found in the African rumba repertoire of many artists from Kinshasa to Dakar, due to the many bolero records that were distributed to radios there as part of the G.V. Series.

The popularity of the genre has also been felt as far as Vietnam, where it became a fashionable song style in South Vietnam before the Fall of Saigon in 1975 and remains popular with Vietnamese.