Raúl Alejandro Ocasio Ruiz was born on January 10, 1993, in San Juan, Puerto Rico and was raised in Canóvanas and Carolina. His father, guitarist Raúl Ocasio, and his mother, backing vocalist María Nelly Ruiz, introduced him to some of his musical influences like Elvis Presley, Michael Jackson, and Chris Brown. For many years, Alejandro and his father lived in the mainland United States, mainly Miami and New York City, where he got inspiration from the R&B and dancehall genres. Rauw Alejandro and fellow Puerto Rican rapper Anuel AA are childhood friends, they both went to the same school and had classes together. As a child, Alejandro competed in school talent shows because he has a passion for dancing. After graduating high school, he enrolled at University of Puerto Rico. From the age of six until he was twenty, he played soccer, but later quit because he (could not perform as he expected to) and suffered an injury at age 20. He moved to Orlando, Florida to attempt to get scouted to play in the Premier Development League (PDL), but eventually was unsuccessful. After quitting soccer, he was left in a light depression, so to improve his mood he decided to switch to a musical career and began to publish songs through SoundCloud in 2014.
In November 2016, he released his debut mixtape titled Punto de Equilibrio. In January 2017, he signed a music deal with Duars Entertainment. In 2018, he was chosen by Sony Music Latin to be part of "Los Próximos", a musical project in which the label sought to enlist new musical talents. The musical project helped him gain fame, and as a result other notable artists noticed him and he was featured in multiple collaborations like Kevin Roldán and Khea's "Pa' Tu Casa”, and "Luz Apagá" by Ozuna, Lunay and Lyanno that year. In December 2017, he released his first single as a lead artist, titled "Toda" with Alex Rose. It peaked at the 29th spot on the Billboard Hot Latin Songs charts in November 2018. A remix of "Toda" featuring Cazzu, Lenny Tavárez, and Lyanno was released in May 2018. The song proved successful, with the music video having over 1 billion views on YouTube as of November 2020. In January 2019, he released his single (Que le dé) with Nicky Jam. In December 2019, his song (Fantasias) with Farruko peaked at the number 12 spot on the US Latin chart, which is also the highest position his songs have reached on the chart, along with (Tattoo). Both songs stayed for 20 weeks on the chart, the highest duration for one of Alejandro's songs to date and won the Latin Grammy Award for Best Urban Fusion/Performance in 2021.
Alejandro's debut album, Afrodisíaco, was released on November 13, 2020. It was preceded by the release of the songs and music videos, (Enchule), the (Elegí) remix, and (Reloj), with Anuel AA.  His second studio album, Vice Versa, released in June 2021, featured the lead single "Todo de Ti". He has won two Latin Grammy Awards from twelve nominations. In February of 2021, Alejandro appeared as Selena Gomez's duet partner on the Hot 100 hit (Baila Conmigo), it also topped the Hot Latin Songs chart. In June he released his third album Vice Versa.