Pelphrey's first notable role was on the CBS soap opera Guiding Light as Jonathan Randall, the son of Reva Shayne and her late former husband, Richard Winslow. He joined the cast in September 2004 and received critical acclaim for his portrayal of anti-hero Jonathan.
He was nominated for a Daytime Emmy Award for "Outstanding Younger Actor" in 2005 and won the award the following year. He received a third consecutive nomination in the same category in 2007 but lost to Bryton McClure. Pelphrey won his second Daytime Emmy Award for "Outstanding Younger Actor" in 2008.
Pelphrey played Mick Dante on As the World Turns from October 2009 to February 2010 when his character was sent to prison for his misdeeds. The role earned Pelphrey an Emmy pre-nomination for Best Supporting Actor.
On March 30, 2007, he appeared in an episode of Numb3rs, "Pandora's Box". On October 17, 2008, he appeared in an episode of "Ghost Whisperer", and the following season in an episode of Law & Order: Special Victims Unit. In 2015 Pelphrey landed the recurring role of Kurt Bunker, a former neo-Nazi trying to reintegrate into society, on Cinemax's action drama Banshee. To prepare for this role he started lifting weights and did research by reading books on the neo-Nazi movement in America. In 2017, he appeared in Iron Fist as Ward Meachum and portrayed Ben Davis on the third season of the Netflix crime drama Ozark which was released on March 27, 2020. His portrayal in the latter received critical acclaim and the lack of an Emmy nomination was perceived as a snub by fans and critics. Nonetheless, Pelphrey received nominations for Critics' Choice Television Award for Best Supporting Actor in a Drama Series, Satellite Award for Best Supporting Actor – Series, Miniseries or Television Film and Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series (shared with the cast). In the final season of Ozark (2022), Pelphrey reprised the role of Ben Davis as a guest appearance, for which he received an Emmy nomination for Outstanding Guest Actor in a Drama Series.
In 2022, he starred on the Amazon Prime Video series Outer Range as Perry Abbott. In 2023, he starred on the HBO miniseries Love & Death as Don Crowder.
From September 6, 2007, to September 30, 2007, Pelphrey performed in Kevin Mandel's A New Television Arrives Finally as the title character, at Theatre 54, in New York. Pelphrey starred in In God's Hat at the Peter Jay Sharp Theater, in New York City, through August 7, 2010. In 2012, he appeared in the Broadway cast of the musical drama End of the Rainbow as Mickey Deans; in 2015, he returned to Broadway in a revival of Fool for Love, playing Martin.
Tom Pelphrey has appeared on Broadway in 2 shows.
Tom Pelphrey has not appeared in the West End.
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