St. John portrayed Todd Manning/Victor Lord Jr. on the ABC daytime drama One Life to Live, and has starred in various primetime shows and films. He is also known for his performances in Patrick Wang's critically acclaimed independent drama films In the Family and The Grief of Others.
On March 12, 2018, St. John was cast as Master Sergeant Jesse Manes on Roswell, New Mexico.
- "It wasn’t an act of love, but this character is so attached [to his son]. I went wherever it took me. I let it take me to a dark place without getting out of control."
- Deadline: ‘Roswell’ Casts Trevor St. John; Megan Ferguson Joins ‘Mixtape’. March 12, 2018.
- Nerds and Beyond: ‘Roswell, New Mexico’ Cast and Creator Talk Season Two and More at ATX TV Fest Panel. June 10, 2019.