Graziadei was born in Germany. He moved to the United States and began acting at the age of 5 in a production of The King and I. On stage, he also appeared in The Servant of Two Masters and History of the Devil. In 2004, he was cast as Daniel Romalotti in the CBS daytime soap opera The Young and the Restless. He is 14 years younger than the actress who plays his mother on the show. In 2013 he left the soap for a career in prime-time television. In 2005 and in 2006, he was nominated for the Daytime Emmy Award for Outstanding Younger Actor in a Drama Series. On film, Graziadei appeared in Boogeyman 2 (2007), Into the Blue 2: The Reef(2009), and The Outside (2009).
Graziadei guest-starred in a number of television series including NCIS, Criminal Minds, 90210, Castle, CSI, and Agents of S.H.I.E.L.D.. He had a recurring role on The CW's The Secret Circle. He now stars in the Lifetime drama series The Lottery, opposite Marley Shelton.