The white doctor in The Gilded Age season 3 episode 8 is Dr. Logan , played by Dylan Baker.

Quick scoop

Episode 8’s cast listings and episode coverage point to Dr. Logan as the white doctor in that finale episode, while the Black doctor who performs the surgery is Dr. William Kirkland, played by Jordan Donica.

Cast note

A season 3 cast guide identifies Dylan Baker as Dr. Logan, the Russell family doctor.

If you want, I can also identify the other doctors and the scene they appear in.