Bradley is an accomplished musician who plays with Bruce Springsteen's famed E Street Band.
Harris has enjoyed a successful career as the lead spokesman for some of the world's largest companies, serving most recently as chief communications officer for the Hillshire Brands Company. He is also a longtime friend and collaborator of Vieira and her husband, Richard.
"Everett and Jon are like brothers to me and will be a great presence as we encourage guests and viewers to be brave and be their true selves," Vieira said in a statement Monday. "They both bring an authentic kindness and a great sense of humor to our friendship that I am eager to share with our audience."
The syndicated, daytime, Monday-through-Friday talk show is to premiere Sept. 8.