Fonseca is a best-selling, award-winning singer and songwriter from Colombia. His music is celebrated for its accessible meld of modern pop styles with traditional Colombian rhythms, evidenced on his charting album Corazón and the singles "Cómo Me Mira" and "Entre Mi Vida y La Tuya." He is also a social activist who uses his voice to fight for social justice. He supported the national program "Canta Conmigo," in which he offered training, lessons, and support to former FARC guerrillas and paramilitaries in the aftermath of a decades-long war. He has also assisted the United Nations in various programs including the "No More Violence Against Women" initiative, and joined his compatriot Juanes in the campaign "Dreaming Is a Right" against the military recruitment of minors.

Fonseca was born in Bogota with the given name Juan Fernando Fonseca. He began studying music before he was ten, and chose the surname-only stage moniker as a child. He sold his first compositions to friends and family by the age of 12. After graduating high school, Fonseca studied music (guitar, voice, and composition) at Javeriana University in Bogota and Berklee College of Music in Boston. Upon returning to Colombia, he began performing and recording demos, one of which came to the attention of Líderes Entertainment Group, a part of EMI Colombia, who signed him in 2001. Fonseca's self-titled debut gained him considerable attention at home. Though neither album nor singles charted, the artist's work nonetheless gained substantial national radio airplay, and consequently, the attention of artists such as Shakira and Juanes, who both offered subsequent collaboration and performance opportunities. Sharing the stage with Shakira on her Mongoose tour, and Juanes at Campin Stadium in Bogota earned Fonseca the recognition and momentum he would need for his second album, 2005's Corazón, which explored the crossroads where pop/rock influences meet the vallenato, bullerengue, and tambora rhythms of his native land. Released by EMI, Corazón was well-received, reaching number six on the Tropical Albums chart, while its singles charted in the Top 20 at Latin Pop and Tropical Songs. Gratitud followed in 2008. Its two singles, "Arroyito" and "Enredame," both charted on the Latin Pop Songs charts and the album peaked inside the Top 10 on the Tropical Albums list.

Already successful, Fonseca rocketed to superstar status with the release of 2011's Ilusion. While the album landed just outside the Tropical Albums Top 10, it was nominated for a Grammy as Best Latin Pop album and won the Latin Grammy for Best Tropical Fusion album. Its charting single, "Desde Que No Estás," was nominated for Tropical Song of the Year. Within four months, the full-length attained quintuple-Platinum status and a Diamond Disc for its sales in Colombia. Fonseca, by then well-known as an ambassador of Colombia's music to the world, recorded Sinfonico in concert with the 100-member-plus Orquesta Sinfonica Nacional de Colombia in 2013, issued a year later as Fonseca Sinfónico con la Orquesta Sinfónica Nacional de Colombia. It was Latin Grammy-nominated for Album of the Year, and won for Best Traditional Pop Vocal Album, becoming his third platinum record for sales in Colombia. It also placed inside the Top 20 on the Classical Albums chart. In early 2015, Fonseca was awarded La Musa Premio Triunfador by the Latin Songwriters Hall of Fame, and in May received the first-ever Contemporary Icon Award at the SESAC Latina Music Awards. In the fall, he released the album Conexión. It charted at number two on the Tropical Albums list thanks to the success of its pre-release singles "Y No Me Faltas" and "Y Tu´" (a duet with Juanes). The set also included a second duet, "Amor Eterno," with Victor Manuelle. The single "Vine a Buscarte" won the 2016 Latin Grammy for Best Tropical Song and was ultimately certified quadruple Platinum. That same year, he issued Homenaje (A la Música de Diomedes Díaz). Produced by Bernardo Ossa, it contained 12 of the best-known songs by the disappeared Colombian singer Diomedes Díaz, rearranged in Fonseca's fusion-pop style. It earned him a Latin Grammy in 2016 for Best Cumbia/Vallenato album. Between the pair, Fonseca hit the Latin Pop Songs chart with four different tracks.

Continuing with his social work, became the first Colombian Goodwill Ambassador for the Save the Children Foundation. In October, via a symphonic concert, he launched his Gratitude Foundation with Camilo Hoyos as director, ensuring the preservation of Colombian cultural traditions. He followed it with a fund-and consciousness-raising tour. In March of 2017, he received an award in the Tropical category for "Vine a Buscarte" during the 25th annual ASCAP Latin Music Awards. In November, Fonseca snuck out the single "Por Pura Curiosidad," which hit airplay and Tropical Songs charts, and was later issued in a special version with participation from ex-Capital Cities vocalist and trumpeter Spencer Ludwig. A second single, "Cuando Llego a Casa," appeared in December as the official theme for the Televisia soap opera Papá a Toda Madre was broadcast in México. Fonseca kicked off 2018 with the single "Porque Nadie Sabe," featuring the Latin Grammy-winning Argentine singer and guitarist Nahuel Pennisi. In May 2018, Fonseca received the Diamond Album Award at the Sony Music Convention in Mexico from Sony Latin chairman and CEO Afo Verde and Sony Music U.S. president Nir Seroussi to commemorate his more than 400 million audio and video streams for the albums Conexion and Ilusion. ~ Evan C. Gutierrez, Rovi