He made his film debut in the independent drama Arresting Gena, then in 1999 played opposite Melissa Joan Hart in Drive Me Crazy and in 2001 starred in James Toback's Harvard Man.

In 2004, Grenier played Vincent Chase in the HBO series Entourage, gaining his most substantial notability and success.

[14] Grenier stepped back in front of the camera in 2015 to reprise his role of Vincent Chase in the Entourage film adaptation.

One of its first, Shot in the Dark, chronicled Grenier's journey to reconnect with his estranged father, Dunbar, with whom his mother broke up when he was still a baby.

Grenier and Dunbar remained estranged for 18 years until he began work on the documentary in an attempt to forge a relationship with him.

On September 27, 2010, HBO premiered Teenage Paparazzo, a documentary directed by Grenier and produced by Bert Marcus.

In addition to its theatrical release, Grenier took the documentary to College campuses nationwide in the Teenage Paparazzo Experience Tour.

It featured actual dealers and celebrities commenting on the subject, including; 50 Cent, Eminem, Susan Sarandon and David Simon, head writer of the HBO series The Wire.

[22] He was a member of two New York bands: the lead singer in Kid Friendly and the drummer in The Honey Brothers[23] before moving on to build Wreckroom, a music incubator, and recording studio in May 2012.

Two bands, Missouri "punk 'n' roll" trio Radkey and metal-spined Brooklyn five-piece The Skins, released EPs on the label in 2013.

The song was inspired by the Russian surrealist classic novel of the same name but SORAYA and Adrian imagined it taking place in contemporary Austin, Texas.

An advocate of sustainable living, Grenier and his business partner and film producer Peter Glatzer founded the lifestyle brand SHFT.com in 2010.

SHFT is a brand that promotes sustainability through film, design, art, and culture and lives both online and offline.

[25] SHFT has partnered with brands such as Ford Motor Company, AOL/Huffington Post, Virgin America, Stonyfield Farm, The W Hollywood, The Weather Channel, and Estée Lauder.