Bentley was born in Jonesboro, Arkansas. He attended the Juilliard School's Drama Division but left the school after one year to pursue his acting career.
Bentley has starred in several films, including the Oscar-winning film American Beauty, The Four Feathers, P2, and Ghost Rider. He starred in the thriller Dolan's Cadillac, based on the short story by Stephen King, and There Be Dragons by director Roland Joffé.
Bentley was one of four subjects in the documentary My Big Break (2009), which documented his immediate fame after American Beauty and his struggles with substance abuse. In 2010, he starred in the premiere of the off-Broadway production Venus in Fur by David Ives. In March 2012, Bentley had a supporting role in the blockbuster movie The Hunger Games, playing game maker Seneca Crane.
In 2012, Bentley also starred with Amber Tamblyn and Vincent Piazza in the indie feature 3 Nights in the Desert directed by Gabriel Cowan. In June 2013, Bentley was selected to star in Ryan Murphy's HBO production titled "Open" along with Scott Speedman.
Work on American Horror Story
He portrayed the eerie ghost Edward Mordrake in the fourth season of American Horror Story, subtitled Freak Show. The following year, he was promoted as regular for the role of detective John Lowe in Hotel. In Roanoke, he portrayed Dylan, an actor re-enacting the ghost Ambrose White in the in-universe mocumentary "My Roanoke Nightmare".
- Wes plays only part-demon on Freak Show but he is all-demon Blackheart in Ghost Rider.
- All of Bentley's characters have become ghost (or portrayed a ghost) in the seasons they appeared.
- Edward Mordrake: Part 1 - Edward Mordrake
- Edward Mordrake: Part 2 - Edward Mordrake
- Curtain Call - Edward Mordrake
- Checking In - John Lowe
- Chutes and Ladders - John Lowe
- Mommy - John Lowe
- Devil's Night - John Lowe
- Room Service - John Lowe
- Room 33 - John Lowe
- Flicker - John Lowe
- The Ten Commandments Killer - John Lowe
- She Gets Revenge - John Lowe
- Battle Royale - John Lowe
- Be Our Guest - John Lowe
- Chapter 1 - Dylan
- Chapter 2 - Dylan
- Chapter 3 - Dylan
- Chapter 4 - Dylan
- Chapter 5 - Dylan
- Chapter 8 - Dylan
- Chapter 9 - Dylan
- Chapter 10 - Dylan