Episode List First Doctor - William Hartnell First Season (Nov 63 to Sep 64) Second Season (Oct 64 to Jul 65) Third Season (Sep 65 to Jul 66) Fourth Season (Sep 66 to Jun 67) Second Doctor - Patrick Troughton Fifth Season (Sep 67 to Jun 68) Sixth Season (Aug 68 to Jul 69) Third Doctor - Jon Pertwee Seventh Season (Jan 70 to Jun 70) Eighth Season (Jan 71 to Jun 71) Ninth Season (Jan 72 to Jun 72) ...