Tom was born and raised in New Jersey. He began acting in high school thanks to a great teacher, and after attending FPAC at Howell High he received a BFA in Acting from Mason Gross School of the Arts at Rutgers University. While at Rutgers he also studied Shakespeare at the Globe Theatre in London, England. In spite of his theater background, Tom's first job was on the long running CBS daytime drama, Guiding Light. While there he won multiple Emmy Awards for his portrayal of Jonathan Randall, the charming and volatile son of the show's leading lady. Tom left the show and spent the next few years working on some independent films and television, but primarily in theater. He was the co-founder and artistic director of the Apothecary Theater Company. They produced the world premier of "In God's Hat", which opened to rave reviews and sold out the rest of its run. The NY Times called the play "terrific" and praised all involved. Pelphrey made his Broadway debut as Micky Deans in "End of the Rainbow", a play about the final days of Judy Garland that was nominated for multiple Tony Awards. He also appeared on Broadway in "Fool for Love" alongside Sam Rockwell and Nina Arianda, meeting and working with Sam Shepard. Tom played Kurt Bunker, a troubled former Neo-Nazi seeking redemption, on the cult-hit action show "Banshee". He was then cast as the wise-ass, drug addicted billionaire Ward Meachum in Marvel's "Iron Fist". Recently, Pelphrey received rave reviews and a lot of attention for his portrayal of Ben Davis on "Ozark"- the bi-polar brother of Wendy (Laura Linney). He was cast as Joseph Mankiewicz in David Fincher's "Mank", brother to Gary Oldman's Herman Mankiewicz. The film was nominated for 10 Academy Awards, the most of any film in 2021.