Keith Szarabajka

Keith Szarabajka is an actor who voiced Joshua Graham In Fallout 4, he voiced several male ghouls and the Vault-Tec scientist, and in its add-on Nuka-World, he voiced John-Caleb Bradberton and Mark Reisman. He also voiced Dr. Edgar Blackburn in the Fallout 76 updates Steel Dawn and Steel Reign.

Background
Szarabajka was almost passed on as the voice of Joshua Graham, because one of the designers involved in the first round of casting suggested removing him from the pool. According to Joshua Sawyer, Szarabajka's submission was "given on a cell phone on a windy day and he had a cold." However, Sawyer decided to keep Szarabajka in the running for the role of Graham, which he considers one of the best decisions he made on the project.