8th: Paul McGann (1996-1999)
9th: Bradley Whitford (1999-2003)
10th Bradley Cooper (2003-2008)
11th: Wendie Malick (2008-2012)
12th Seth McFarlane (2012-2016)
13th Kal Penn (2017-2019) (cancelled due to low ratings)
animated reboot
14TH Patricia Summersett (2023-)
8/25/21 retcon the show is is no longer cancelled then revived, instead after McFarlane Misha Collins takes over from 2016 to 2019 necessitating his departure from supernatural early in this universe then he announces his resignation in 2019 leaving in the 2020 new years/Christmas special to be replaced by unknown comedienne Kathryn Hahn evoking a portrayal similar to Malick's who at this point is considered this universes definitive doctor alongside Tom Baker, Sylvester McCoy and Bradley Cooper. Also bc of her involvement with DW overlapping with the schedule Hahn dosen't get cast as Agatha Harkness in this Universe. And instead of Ben Schwartz as a companion its Jensen Ackles.
/10/21 retcon: i switched Misha out for Julian Richings and Hahn for Abigail Spencer.