He was born in Avezzano (L'Aquila) on August 5, 1974. After graduating from high school at the Istituto Alessandro Torlonia, he moved to Rome to attend college and obtained a degree in film studies at Rome's Università "La Sapienza." He then attended a screenwriting course at the Università "La Sapienza" taught by Orio Caldiron, Sandro Petraglia, Francesco Bruni, and Furio Scarpelli, followed by a course in creative writing at the same university, taught by Vincenzo Cerami.
He began his professional career in 1999, when he made a 35mm short film called "Dove corri, ma dove corri?!", and followed it up with his next short, also a 35mm, entitled "Io ci provo."
To become better acquainted with film sets, Chiantini served as assistant director on the film "Incantesimo napoletano" by Paolo Genovese and Luca Miniero, as well as on Vincenzo Marra's documentary "Paesaggio a sud."
He returning to directing in 2004, when he wrote and directed the super 16mm feature film "Forse si...forse no...", starring Alessandro Tiberi, Luciano Federico, and Cristiana Capotondi and produced by Mariposa Film and Gianluca Arcopinto. This film was selected to represent Italian first films at the Young European Directors Festival in Budapest and the Bratislava Film Festival; it also screened in the independent Italian film section at the Pesaro Film Festival before its Italian release in 2004, distributed by Pablo.
In 2007 Chiantini wrote and directed his second feature film, "L'amore non basta," shot in super 16mm, starring Giovanna Mezzogiorno, Alessandro Tiberi, Rocco Papaleo, Alessandro Haber, Ivan Franek and Marit Nissen. The film was produced by Obraz Film and Liupo Film and distributed by Media Film in 2008.
Before turning to his third feature, "Islands," he tried his hand at documentaries, writing and directing the documentary "Quarto tempo" in 2010. Produced by Obraz Film, it is currently in post-production.