

Since this came up in another thread, I felt the topic deserved its own--Both for the sake of discussion and clearing things up. There are currently 14 known on-screen continuities/timelines in the Godzilla film series:
SHOWA CONTINUITY
Godzilla '54
Godzilla Raids Again
Rodan
Varan
Mothra
King Kong vs. Godzilla
Atragon*
Mothra vs. Godzilla
Ghidorah: The Three Headed Monster
Frankenstein Conquers the World*
Monster Zero
War of the Gargantuas*
Godzilla vs. The Sea Monster
King Kong Escapes*
Son of Godzilla
Godzilla vs. Hedorah
Godzilla vs. Gigan
Godzilla vs. Megalon
- Zone Fighter (TV series)
Godzilla vs. MechaGodzilla
Terror of MechaGodzilla
Destroy All Monsters
- 2075: Meister Titano's Counterattack (short story)
*Possibly not in continuity depending on the source.
ALL MONSTERS ATTACK CONTINUITY
All Monsters Attack
HEISEI CONTINUITY
Godzilla '54
The Mysterians
The Return of Godzilla
Godzilla vs. Biollante
Godzilla vs. King Ghidorah
Godzilla vs. Mothra
Godzilla vs. MechaGodzilla II
Godzilla vs. SpaceGodzilla
Godzilla vs. Destoroyah
TRISTAR CONTINUITY
Godzilla '98
- Godzilla: The Series (TV Series)
GODZILLA 2000 (G2K) CONTINUITY
Godzilla '54
Godzilla 2000
GODZILLA X MEGAGUIRUS (GXM) CONTINUITY
Godzilla x Megaguirus
GODZILLA, MOTHRA, KING GHIDORAH (GMK) CONTINUITY
Godzilla '54
Godzilla '98*
Godzilla, Mothra, King Ghidorah: Giant Monsters All-Out Attack
*Possibly not in continuity depending on the source.
KIRYU SAGA (GXMG & GMMG) CONTINUITY
Godzilla '54
Rodan
Varan
Mothra
Gorath
Atragon
Dogora
Frankenstein Conquers the World
War of the Gargantuas
King Kong Escapes
Yog: The Monster From Space
Godzilla x MechaGodzilla
Godzilla: Tokyo S.O.S.
GODZILLA: FINAL WARS CONTINUITY
Godzilla: Final Wars
MONSTERVERSE CONTINUITY
- Godzilla: Awakening (comic)
Kong: Skull Island
- Skull Island: The Birth of Kong (comic)
Godzilla '14
- Godzilla: Aftershock (comic)
Godzilla: King of the Monsters
- Godzilla Dominion/Kingdom Kong (comic)
Godzilla vs. Kong
SHIN GODZILLA CONTINUITY
Shin Godzilla
GODZILLA ANIME CONTINUITY
- Godzilla: Monster Apocalypse (novel)
- Godzilla: Project MechaGodzilla (novel)
Godzilla: The Planet of Monsters
Godzilla: City on the Edge of Battle
Godzilla: The Planet Eater
- Television-led Continuities:
HANNA-BARBERA CONTINUITY
- Godzilla
- Scooby-Doo Team-Up #43 (comic)
SINGULAR POINT CONTINUITY
- Godzilla Singular Point

Ah, so my stupidity has served a purpose! Thank you!
If people weren't lazy, we wouldn't try to be efficient. If we weren't efficient, we'd never get anything done.

Outstanding move.
Zwei Wing is the best singing duo. Change my mind.

I've only seen the beginning ten min. of War of The Gargantuas.

Godzilla: Making cinematic universes and continuity reboots before Marvel and DC made it cool.
A true fan can acknowledge the bad while still appreciating and cherishing the good.

The GCU

^Not wrong.

... I'm going to use that today.
If people weren't lazy, we wouldn't try to be efficient. If we weren't efficient, we'd never get anything done.

dk,
Such a debate has never been an issue because they're all canon to their specific continuities--There is no singular canon.
Example: Godzilla vs. Biollante is canon to the Heisei Continuity, but not any other. Simple as that.

HEISEI CONTINUITY
Godzilla '54
Godzilla vs. Biollante
Godzilla vs. King Ghidorah
Godzilla vs. Mothra
Godzilla vs. MechaGodzilla II
Godzilla vs. SpaceGodzilla
Godzilla vs. Destoroyah
umm shouldnt Godzilla 84 be in there i mean Biolante was a direct continuation from 84

The MCU and DCEU are nothing compared to the "GCU".

XarKhaan,
Good catch. Didn't realize I had missed that one. Corrected.

Some people believe Godzilla 54 is part of the Megaguirus continuity.

I like the approach of just having there be different timelines rather than bringing canon into it. Especially for a series as big as godzilla.

The true shark boy,
The movie shows and explains explicitly different events that took place in 1954. Godzilla looked like the MireGoji in 1954 and was not killed by the Oxygen Destroyer.

I just told my entire english class about the symbolism of Godzilla 1954, and the effects of nuclear power.
Zwei Wing is the best singing duo. Change my mind.

@Gmkgoji,
That's cool! What did they think about it?

The debate rages on over the Megagurius continuity. Some Toho sources include G'54--If only as an alternate version of the events.

Added Singular Point to the list. As well as the Hanna-Barbera continuity and The Mysterians to the Heisei continuity.