Ramón "Mongo" Santamaría Rodríguez was born in Havana on April 7, 1917, and grew up in the Jesús María district, where rumba and the drumming of Afro-Cuban religious ceremonies were part of street life. He learned the congas as an amateur rumba player and the bongos from Clemente "Chicho" Piquero, a drummer in Beny Moré's band who later recommended him for a Mexican tour. He took up violin first, according to the Guardian and AllMusic, before switching to drums and leaving school in his teens. He played bongos with the Septeto Beloña from 1937, worked in the house band of the Tropicana nightclub in the 1940s, and toured with groups such as the Lecuona Cuban Boys and Sonora Matancera.

He moved to New York in 1950 and made his American debut in the orchestra of Pérez Prado, then spent about six years as the conga player in Tito Puente's band. His first records as a leader date from those years: Afro-Cuban Drums, a 10-inch LP of folkloric rumba recorded in New York on November 3, 1952 for SMC Pro-Arte, and a Changó record for Tico built on Santería chants. They are among the first recorded folkloric rumbas, and his later albums for jazz labels kept that music in print. In 1957 he went to San Francisco to join the vibraphonist Cal Tjader's Latin jazz group, with Al McKibbon on bass, Vince Guaraldi on piano and Willie Bobo and Armando Peraza among the percussionists. He stayed until 1960 and is on Tjader's Fantasy albums of 1958 and 1959, including Cal Tjader's Latin Concert and A Night at the Black Hawk.

Fantasy also gave him his own start. Yambu (1958) presented his Ritmos Afro-Cubanos, a charanga band, and its follow-up Mongo (1959) carried "Afro Blue," his own composition and the first jazz standard built on an African 3:2 cross-rhythm. Oscar Brown Jr. wrote lyrics for it in 1959, Abbey Lincoln recorded the vocal version that year on Abbey Is Blue, and John Coltrane recorded it in 1963 with Elvin Jones, who turned the rhythm over into a swung 3/4. In 1960 Santamaría went to Havana with Bobo to make Our Man in Havana and Mongo in Havana, then returned to New York and formed the charanga La Sabrosa, which gave Fantasy ¡Sabroso! (1960) and ¡Arriba! La Pachanga (1961) as the pachanga dance craze peaked. At Riverside he led the Afro-Latin Group on Go, Mongo! (1962), with the saxophonist Pat Patrick and the young pianist Chick Corea, whose first recorded credit was on the album.

The record that made him a household name came out of a quiet night in a Bronx club in late 1962. Corea had given notice, and Herbie Hancock sat in for a weekend. Prompted by Donald Byrd, Hancock played "Watermelon Man," a blues from his debut album Takin' Off. Santamaría joined in on congas, the band caught the groove and the dance floor filled. He recorded it on December 17, 1962 with the producer Orrin Keepnews, and it was issued on Battle Records, the label the Riverside owners had taken over that year. It reached No. 10 on the Billboard Hot 100 in April 1963 and entered the Grammy Hall of Fame in 1998. The single is often treated as the beginning of boogaloo, the Afro-Cuban and rhythm and blues mixture that dominated New York's Latin dance floors for the next few years. The album Watermelon Man! (1963) also held the first recording of "Yeh-Yeh," written by the pianist Rodgers Grant and Patrick and later a No. 1 hit in Britain for Georgie Fame. Two more albums followed in 1963: Mongo at the Village Gate on Battle and Mongo Introduces La Lupe on Riverside, which presented the singer La Lupe.

From 1965 to 1970 Santamaría recorded for Columbia, beginning with El Pussy Cat and continuing through La Bamba, El Bravo!, Hey! Let's Party, Mongomania, Soul Bag and Workin' on a Groovy Thing. The records paired the trumpeter Marty Sheller's brassy charts with covers of the day's hits, among them "Cold Sweat," "Sitting on the Dock of the Bay," "In the Midnight Hour" and "I Got You (I Feel Good)." His bands of the decade were a training ground: Hubert Laws played tenor saxophone with him in the mid-1960s, the saxophonists Pat Patrick and Sonny Fortune also worked for him, and Nat Adderley and Jimmy Cobb were billed as featured guests on Mongo Explodes (1966). Albums for Atlantic followed from 1970, among them Mongo '70, Mongo at Montreux and Mongo's Way.

In the 1970s he moved to Vaya, the Fania label, and returned to Afro-Cuban material: Fuego (1973), Afro-Indio (1975), Sofrito (1976) and Dawn (Amanecer) (1977). He became a member of the Fania All-Stars, often trading conga solos with Ray Barretto, who had taken his chair in Puente's band in 1957. He was nominated for the Grammy for Best Latin Recording for Afro-Indio and Sofrito, and won it at the 20th Grammy Awards in February 1978 for Dawn. He was nominated again for A la Carte and for the Pablo Live album Summertime, recorded at Montreux in 1980 with Dizzy Gillespie and Toots Thielemans.

His last decade of recording was split between Latin jazz labels. Concord Picante released several albums between 1987 and 1990, including Soy Yo and Live at Jazz Alley, Chesky issued Mambo Mongo in 1993, and in 1995 he returned to Fantasy through its Milestone imprint for Mongo Returns!. He was inducted into the International Latin Music Hall of Fame in 2000 and the Billboard Latin Music Hall of Fame in 2001. Health problems ended his touring in the late 1990s, and he kept the Upper West Side apartment he had moved into in 1964. Santamaría passed away in Miami on February 1, 2003, after a stroke, at the age of 85.

Santamaría played with a hypnotic calm. AllMusic's Richard S. Ginell described concerts in which he seated himself quietly behind the congas and soloed over an endless band vamp, drawing on the spell of Cuban religious ritual, and the Guardian's obituary credited him with widening the technical and imaginative scope of conga and percussion playing. He did not analyze his own style, saying that when he played he did not know how he did it. His roots were in the rumba of the Havana streets and the chants of Santería, which he put on record in the 1950s more directly than almost any other Cuban in New York. As a bandleader he worked with the charanga lineup of flute and violin, then with jazz brass and saxophones, and at times with electric instruments, always keeping a clave-based rhythm section under a jazz soloist's front line.

The jazz and pop side of his career was real and sizable. "Afro Blue" became a repertory piece for John Coltrane and many singers, and the Latin-soul records on Columbia and Atlantic, built on R&B and rock covers, helped create the boogaloo and Latin-soul sound that preceded salsa. In his last decades he insisted that what the press called salsa was the Afro-Cuban music he had been playing for fifty years. Much of his output is dance music rather than improvised jazz: the pachanga, boogaloo, soul and salsa records sit beside the Fantasy and Pablo jazz dates, and his jazz credentials rest on "Afro Blue," his years with Cal Tjader and Tito Puente, and a long line of jazz sidemen.