Born in Tulsa, Oklahoma, USA and raised in Grand Prairie, Texas, Billy is the middle child, and only son, of three children. As a child, Miller spent five years as a patient of Texas Scottish Rite Hospital for Children, an organization he now supports.
He attended Mirabeau. B Lamar High School in Arlington, Texas and the University of Texas in Austin, Texas, where he received a communications degree and was one of only twenty students in the film department's intensive Production Sequence.
After graduating from college, Miller moved out to Los Angeles where he began working in mail room of Industry Entertainment. His first break into acting came after he signed on with the Wilhelmina modeling agency. He appeared in six commercials, including two for Electronic Arts' The Sims. He also did commercials for JC Penney, Pizza Hut and pokerparty.com.
At the age of 24, he screen-tested for the CBS Daytime soap opera As The World Turns, but due to bad management, he lost the audition, and subsequently the management and agency. He took a two-year hiatus from acting after that experience.
In 2006, Billy returned to acting, starring in an episode of CSI: NY. A year later, he landed the role of Richie Novak, the murdering, and blackmailing brother of Annie Lavery on the ABC Daytime soap opera All My Children. His first appearance on-screen was August 30, 2007. When news of the character's demise broke in August 2008, Miller began the audition process again. Barbara Bloom (Senior Vice President, Daytime, CBS Entertainment), Julie Hanan Carruthers (Executive Producer, All My Children), Marla Kanelos (former Script Writer, All My Children, now Associate Head Writer, The Young and the Restless), and screen-test partners Peter Bergman and Elizabeth Hendrickson were instrumental in helping him get the job at The Young and the Restless.
Billy's last appearance as Richie Novak on All My Children coincided with his first appearance as Billy Abbott on The Young and the Restless on September 19, 2008. He is the fourth contract actor to fill the role, a role that had been met with varying degrees of success in its three previous attempts to recast the part. Miller, who submitted the longest Emmy reel among all nominated performers (over 32 minutes long—an entire episode), was awarded for his work in an It's A Wonderful Life-styled episode of The Young and the Restless with his first Daytime Emmy Award nomination and win as Outstanding Supporting Actor in a Drama Series on June 27, 2010. Miller was released from his contract from the show and replaced by David Tom (who was the first actor to portray Billy) on February 3, 2014.
In 2011, he was nominated a second time in the Outstanding Supporting Actor category for the same role.
He also appears, as himself, in an independent film titled Remembering Nigel, which premiered at the Paso Robles Digital Film Festival on November 25, 2009.
In August, it was confirmed that Miller would be appearing in primetime as a recurring cast member on the CW Network’s thriller Ringer.