[The Fourth Season began with the First Doctor] EE. The Power of the Daleks X 1. Episode One 5 Nov 66 X 2. Episode Two 12 Nov 66 X 3. Episode Three 19 Nov 66 X 4. Episode Four 25 Nov 66 X 5. Episode Five 3 Dec 66 X 6. Episode Six 10 Dec 66 FF. The Highlanders X 1. Episode 1 17 Dec 66 X 2. Episode 2 24 Dec 66 X 3. Episode 3 31 Dec 66 X 4. Episode 4 7 Jan 67 GG. The Underwater Menace X 1. Episode 1 14 Jan 67 2. Episode 2 21 Jan 67 3. Episode 3 28 Jan 67 X 4. Episode 4 4 Feb 67 HH. The Moonbase X 1. Episode 1 11 Feb 67 2. Episode 2 18 Feb 67 X 3. Episode 3 25 Feb 67 4. Episode 4 4 Mar 67 JJ. The Macra Terror X 1. Episode 1 11 Mar 67 X 2. Episode 2 18 Mar 67 X 3. Episode 3 25 Mar 67 X 4. Episode 4 1 Apr 67 KK. The Faceless Ones 1. Episode 1 8 Apr 67 X 2. Episode 2 15 Apr 67 3. Episode 3 22 Apr 67 X 4. Episode 4 29 Apr 67 X 5. Episode 5 6 May 67 X 6. Episode 6 13 May 67 LL. The Evil of the Daleks X 1. Episode 1 20 May 67 2. Episode 2 27 May 67 X 3. Episode 3 3 Jun 67 X 4. Episode 4 10 Jun 67 X 5. Episode 5 17 Jun 67 X 6. Episode 6 24 Jun 67 X 7. Episode 7 1 Jul 67
MM. The Tomb of the Cybermen
1. Episode 1 2 Sep 67
2. Episode 2 9 Sep 67
3. Episode 3 16 Sep 67
4. Episode 4 23 Sep 67
NN. The Abominable Snowmen
X 1. Episode One 30 Sep 67
2. Episode Two 7 Oct 67
X 3. Episode Three 14 Oct 67
X 4. Episode Four 21 Oct 67
X 5. Episode Five 28 Oct 67
X 6. Episode Six 4 Nov 67
OO. The Ice Warriors
1. One 11 Nov 67
X 2. Two 18 Nov 67
X 3. Three 25 Nov 67
4. Four 2 Dec 67
5. Five 9 Dec 67
6. Six 16 Dec 67
PP. The Enemy of the World
X 1. Episode 1 23 Dec 67
X 2. Episode 2 30 Dec 67
3. Episode 3 6 Jan 68
X 4. Episode 4 12 Jan 68
X 5. Episode 5 20 Jan 68
X 6. Episode 6 27 Jan 68
QQ. The Web of Fear
1. Episode 1 3 Feb 68
X 2. Episode 2 10 Feb 68
X 3. Episode 3 17 Feb 68
X 4. Episode 4 24 Feb 68
X 5. Episode 5 2 Mar 68
X 6. Episode 6 9 Mar 68
RR. Fury From the Deep
X 1. Episode 1 16 Mar 68
X 2. Episode 2 23 Mar 68
X 3. Episode 3 30 Mar 68
X 4. Episode 4 6 Apr 68
X 5. Episode 5 13 Apr 68
X 6. Episode 6 20 Apr 68
SS. The Wheel in Space
X 1. Episode 1 27 Apr 68
X 2. Episode 2 4 May 68
3. Episode 3 11 May 68
X 4. Episode 4 18 May 68
X 5. Episode 5 25 May 68
6. Episode 6 1 Jun 68
TT. The Dominators
1. Episode 1 10 Aug 68
2. Episode 2 17 Aug 68
3. [no on screen episode title] 24 Aug 68
4. Episode 4 31 Aug 68
5. Episode 5 7 Sep 68
UU. The Mind Robber
1. Episode 1 14 Sep 68
2. Episode 2 21 Sep 68
3. Episode 3 28 Sep 68
4. Episode 4 5 Oct 68
5. Episode 5 12 Oct 68
VV. The Invasion
X 1. Episode One 2 Nov 68
2. Episode Two 9 Nov 68
3. Episode Three 16 Nov 68
X 4. Episode Four 23 Nov 68
5. Episode Five 30 Nov 68
6. Episode Six 7 Dec 68
7. Episode Seven 14 Dec 68
8. Episode Eight 21 Dec 68
WW. The Krotons
1. Episode One 28 Dec 68
2. Episode Two 4 Jan 69
3. Episode Three 11 Jan 69
4. Episode Four 18 Jan 69
XX. The Seeds of Death
1. Episode One 25 Jan 69
2. Episode Two 1 Feb 69
3. Episode Three 8 Feb 69
4. Episode Four 15 Feb 69
5. Episode Five 22 Feb 69
6. Episode Six 1 Mar 69
YY. The Space Pirates
X 1. Episode One 8 Mar 69
2. Episode Two 15 Mar 69
X 3. Episode Three 22 Mar 69
X 4. Episode Four 29 Mar 69
X 5. Episode Five 5 Apr 69
X 6. Episode Six 12 Apr 69
ZZ. The War Games
1. Episode One 19 Apr 69
2. Episode Two 26 Apr 69
3. Episode Three 3 May 69
4. Episode Four 10 May 69
5. Episode Five 17 May 69
6. Episode Six 24 May 69
7. Episode Seven 31 May 69
8. Episode Eight 7 Jun 69
9. Episode Nine 14 Jun 69
10. Episode Ten 21 Jun 69