Conjunto Casino was a prominent Cuban musical group that played a significant role in the popular music scene of the 1940s and 1950s. Originating in Cuba, the band initially started as a sextet known as Sexteto Casino around 1933, founded by brothers José and Manolo Saldarino. On May 1, 1937, they adopted the name Conjunto Casino when they became the resident band of the Summer Casino or Gran Casino Nacional de Marianao in Havana.

The band's music style was a blend of son montuno, guaracha, bolero, guajira, conga, rumba, guaguancó, and cha cha chá, with a particular inclination towards jazz harmonies, especially bebop and swing. This made them part of the more progressive son ensembles of their time. Conjunto Casino was influential in shaping the sound of many other Cuban groups that followed, such as Conjunto Colonial and Conjunto Rumbavana.

Throughout their active years, the group underwent several changes in its lineup and sound. In 1940, Esteban Grau took over as the leader, bringing in new members like contrabassist Cristóbal Doval and singer Roberto Espí. Espí was instrumental in the group's evolution, including the adoption of the name Conjunto Casino for their recordings with RCA Victor starting in 1942.

The vocal harmonies of Roberto Faz, Roberto Espí, and Agustín Ribot were particularly popular between 1946 and 1951. They performed at notable venues like the Zombie Club in Havana and made several recordings for RCA Victor and Panart, further cementing their place in Cuban music history.

Conjunto Casino remained active until the mid-1980s, leaving behind a legacy of recordings and performances that continue to influence Cuban music. Their discography includes numerous albums, singles, and compilations, with notable releases such as "A Bailar Con El Conjunto Casino" and "El Original Conjunto Casino Faz - Ribot - Espi."