Gianni was born in Los Angeles, California and resides in the Santa Clarita Valley with his older brother, Anthony, and his parents who run a Respite Agency primarily for people with developmental disabilities, as his older brother Anthony himself is on the Autism Spectrum and works with severe OCD. Gianni once used his brother's autistic traits for a part he played as a young schizophrenic.
Raised in the arts, due to the fact that his parents met in an acting class, at age 8, Gianni approached his mother and asked when HE could be on TV. Taking that as her cue, his mother took some pictures in the back yard, and secured him immediate representation.
The early years required a lot of self-promoting and "pro-bono" work on Gianni's part, which included Student Films.
Gianni's first paying gig came in the form of a non-union insurance commercial where he acted opposite a 6,000 lbs. juvenile elephant named "Suzy". Better representation followed, and Gianni's resume quickly grew.
Cobra Kai(2018)as Demetri, Demetri Alexopoulos
He's Watching You(2024)as Cavalli
NCIS: Los Angeles(2009)as Luke Austin
Cobra Kai 2: Dojos Rising(2022)as Demetri Alexopolous
NCIS(2003)as Owen
Jud's Decision(2019)
InStyle: YouTube Channel(2007)as Self
Cobra Kai Canada(2022)as Self - Gianni DeCenzo
Still Watching Netflix(2014)as Self
The Hollywood Reporter(2008)as Self
Courageous Nerd(2020)as Self
