I know who's gonna be on the throne in the end. I'd better not say. There'll be a few people sitting on it before the answer. -SSM, Emmy Panel: March 2013

and:

It wasn't easy for me. I didn't want to give away my books. It's not easy to talk about the end of my books. Every character has a different end. I told them who would be on the Iron Throne, and I told them some big twists like Hodor and 'hold the door,' and Stannis's decision to burn his daughter. We didn't get to everybody by any means. Especially the minor characters, who may have very different endings." -SSM, Screenrant Article: 10 October 2020

In this post I thought it would be fun to do a quick rundown of the different characters who could sit the Iron Throne before the end of the series.

Who All Sits the Iron Throne Before the End?

a chair that could kill a man, and had, if the stories could be believed.

Note: Throughout history we have had numerous kings and claimants. But due to the number claimants, possible the goal of this post is to stick to people who actually "on the throne".

Current King

Tommen I Baratheon

The current king (gods bless his little heart). His marriage to Maergary is what holds the Lannister/Tyrell alliance together. At some point, Tommen will die:

The old woman was not done with her, however. "Gold shall be their crowns and gold their shrouds," she said. "And when your tears have drowned you, the valonqar shall wrap his hands about your pale white throat and choke the life from you." -AFFC, Cersei VIII

After Tommen (if we follow the quote verbatim) there will be a couple others. I don't expect all of the below to sit the throne, I am just presenting options.

Familial Successors

Myrcella I Baratheon

As we see in the above quote, we can expect Myrcella to be crowned and die as well. She has technically already been crowned in Dorne

Cersei I

TWOW, Mercy does refer to Harys Swyft being sent by a "queen", although this is quite ambiguous and the chapter is likely to have had some revisions.

The biggest problem with Cersei is how little support she has available to her in King's Landing. If the Tyrells are no longer bound to her, she basically has Qyburn/unGregor and some guardsmen.

Stannis I Baratheon (not technically familial)

Extremely unlikely in my opinion, but I thought I would mention him just due to the effort I expect him to put in to try.

Return of the Dragons

Aegon VI

Due to the foreshadowing we get in THOTU, I think that Young Griff becoming king makes sense (even he doesn't hold the throne for very long).

If interested: Young Griff and King's Landing

Daenerys I

The Queen Across the Water returns to Westeros aback a dragon (with up to 2 more dragonriders on her side).

Other Possibilities

Euron I Greyjoy

During Aeron's Shade of the Evening trip, he sees Euron seated on the Iron Throne:

“The bleeding star bespoke the end,” he said to Aeron. “These are the last days, when the world shall be broken and remade. A new god shall be born from the graves and charnel pits.” Then Euron lifted a great horn to his lips and blew, and dragons and krakens and sphinxes came at his command and bowed before him. “Kneel, brother,” the Crow’s Eye commanded. “I am your king, I am your god. Worship me, and I will raise you up to be my priest.”

“Never. No godless man may sit the Seastone Chair!”

“Why would I want that hard black rock? Brother, look again and see where I am seated.”

Aeron Damphair looked. The mound of skulls was gone. Now it was metal underneath the Crow’s Eye: a great, tall, twisted seat of razor sharp iron, barbs and blades and broken swords, all dripping blood.

Impaled upon the longer spikes were the bodies of the gods. The Maiden was there and the Father and the Mother, the Warrior and Crone and Smith … even the Stranger. They hung side by side with all manner of queer foreign gods: the Great Shepherd and the Black Goat, three-headed Trios and the Pale Child Bakkalon, the Lord of Light and the butterfly god of Naath. -TWOW, The Forsaken

This could just be imagery, but who knows. Euron does seem to have goals even bigger than the Iron Throne though.

The End

Edmure Tully isn't going to volunteer lol.

Bran Stark

As we know GRRM told D&D who would be on the Iron Throne at the end:

I told them who would be on the Iron Throne

which to me (and plenty others) doesn't make a ton of sense. So I tend to interpret it as the "end" being set way in the future with Bran as some type of last greenseer/king.

It should be noted that spouses/betrothals between the above can happen as well.

TLDR: Nothing new. Just a quick rundown on some possibilities on the Iron Throne between Tommen and Bran.