Isabella Castillo Díaz is a Cuban actress, singer and dancer best known for her role as Graciela "Grachi" Alonso, the lead character of the Nickelodeon fantasy television series Grachi, for which has released several songs. Castillo has also starred on the telenovelas Tierra de reyes, El Señor de los Cielos and Malverde: El Santo Patrón, as well as the musical film La Usurpadora: The Musical.

Grachi is a Spanish language American fantasy series produced by Nickelodeon created by Mariela Romero. The series stars Isabella Castillo as Grachi and Andrés Mercado as Daniel; also featuring and Kimberly Dos Ramos, Mauricio Henao, Sol Rodríguez and Lance Dos Ramos in supporting roles. The series was filmed in Miami, Florida, United States, becoming the first Nickelodeon Latin American series to be recorded out of Latin America, and also the first to be recorded on high definition. It premiered in Nickelodeon Latin America on May 2, 2011. In June 2011, it was confirmed that the series was renewed for a second season, which began airing on February 27, 2012. In June 2012, the series was renewed for a third and last season of 50 episodes, which aired from March 4 to May 10, 2013.