From 2021 to 2023, Agustín Sierra was in a relationship with Fiorella Giménez, his dance partner in the program of Bailando 2021.

In 2002, he made a special appearance in the youth television series Rebelde Way starring Camila Bordonaba, Felipe Colombo, Luisana Lopilato and Benjamín Rojas.

In 2003, he was part of the cast of the children's television series Rincón de Luz starring Guido Kaczka and Soledad Pastorutti.

From 2004 to 2005, he was part of the cast of the youth television series Floricienta starring Florencia Bertotti, Juan Gil Navarro and Fabio Di Tomaso.

In 2006, he made a special appearance in the children's television series Chiquititas Sin Fin.

2014-2016 conducio Fans en Vivo In 2017, he made a special appearance in the television Golpe al corazón.