Golarion
Golarion is the "main" planet in Paizo's default campaign setting for the Pathfinder Roleplaying Game. It's not the sum total of the setting's Material Plane like, say, Toril is, but it's where most of the action is and where you're going to be spending most of your time so it's also the nickname for what's properly known as the Pathfinder Campaign Setting. Golarion was first introduced to players as a generic OGL module named Crown of the Kobold King, released in June of 2007 under Paizo's GameMastery imprint. Two months later at Gen Con 2007, Paizo published Rise of the Runelords, the first of Pathfinder's famous Adventure Paths and the first product to bear the Pathfinder brand name; this was followed by another adventure path and a couple "Pathfinder Chronicles" supplements. When Wizards announced Dungeons & Dragons 4th Edition and neglected to mention that the OGL would be replaced with a giant spiky dildo, Paizo cashed in on the confusion and announced that they would be creating a replacement RPG, based on OGL content but with a less restrictive license for its "Product Identity" and with Golarion as the default setting. Golarion is notable for ripping off fucking everything, including dime-store pulp novels, random bits of relatively modern history, earlier editions of D&D, sci-fi kitsch, and the kitchen sink. This is a transparent attempt to fill the gaping orifice left behind by the loss of the D&D's "Product Identity" as cheaply as possible, justified as a way of allowing many different campaign styles to coexist in the same setting. One notable exception is the elder gods of the Far Realm, which Paizo replaced by biting the bullet and licensing the Cthulhu Mythos from Chaosium.
The centerpiece of Golarion is the Inner Sea region, consisting of the fantasy equivalents of Western Europe, the Mediterranean Sea zone, and the northern half of Africa. Unlike most other fantasy settings, many of the cultures and civilizations of the Inner Sea region are in severe decline after the only deity which represents humans in the Great Beyond, Aroden, died a few centuries ago. To add salt to the wound, this caused a series of events which fucked up the world: the formation of a massive supernatural stationary fuckstorm that annihilated two entire nations and allowed pirates to develop their own kingdoms, the obliteration of a noble barbarian empire by a tear in the tissue of reality opened directly into the Abyss, and the prophets and diviners committing mass suicide as an prophesied golden age for mankind suddenly faded into nothing. As if this wasn't enough, the religious hysteria led the two greatest empires of the region to become balkanized devil-worshipping fantasy Nazis and decadent chucklefucks, respectively.
Nations of Golarion
Absalom
Mecca meets Sigil in the middle of the ocean. 10,000 years in Golarion's past, a fuckhuge magic space rock called the Starstone struck the planet, creating the Inner Sea in the process and destroying Azlant, home of the Glorious Azlanti Master Race. The last of the Azlanti, Aroden, lifted the stone out of the Inner Sea 5,000 years later and used its magic to become the God of Humanity in living flesh, founding the city-state of Absalom on the island where he dumped the thing to protect it from others who wanted to pull the same trick. It's still there, in the heart of the Ascendant Court, and anyone who survives the Test of the Starstone can use it to become a god too. (Thousands try every year; only three have ever succeeded, including one guy who took the test on a drunken dare and can't remember how he did it.) As everyone has a stake in keeping the number of crazy gods around to a minimum and the island is strategically located in the middle of the Inner Sea, Absalom has become the effective center of civilization in Golarion's western hemisphere, with a complete clusterfuck of races and nationalities walking the streets to wheel and deal. Other areas of note include the Cairnlands, the slightly-haunted graveyard for all the dumbasses who tried and failed to invade one of the most important places on the planet, and the Ivy District, which is where all the whores are and where everyone goes to stab each other in the back.
Alkenstar
Fuck yeah guns in your fantasy setting. Alkenstar is in the middle of a giant non-magical desert formed by a war between its magocratic neighbors, so they had to tell Medieval Stasis to shove it and learn engineering to stay relevant. Almost all of Golarion's gunpowder-based weaponry is produced by Alkenstari engineers, and they like to keep it that way so they can continue to charge out the ass for them. This is so your GM has an excuse to veto firearms. Despite what you'd expect from a desert nation that shits firearms, they're not particularly friends with Andoran, maintaining scrupulous neutrality and being situated in Golarion's equivalent of northeastern Africa.
Andoran
Fuck yeah 'Muricans. When Cheliax shat the bed, the nobles of Andoran went along with their new devil overlords in the interest of not becoming a fucking bloodbath like Galt or Cheliax itself. Andoran's burgeoning merchant class had other ideas and whipped up a revolution two years later, using Galtan philosophy (as if the American Revolution parallels weren't fucking obvious enough) to fuel the fires and inventing democratic socialism and the welfare state from whole cloth. As expected of fantasy Americans, they also practice cultural imperialism, actively exporting their radical ideology and disrupting the Inner Sea's slave trade. This makes them less than popular with the rest of the world. Their patron divinity is a celestial eagle-man.
Belkzen
Stupid dumb greenskin scum. When Golarion's dwarves took their expedition/holy war out of the Darklands, they brought the orcs with them. The dwarves eventually pushed them back into a shitty little valley in the continent's north, but not before a strong and ambitious orc warlord named Belkzen managed to capture and ransack a Dwarf Fortress that he rechristened Urgir, the closest thing to a capital city they have. Naturally, the Hold of Belkzen has since collapsed into a fuckpile of semi-nomadic tribes with friendly names like Broken Spine, Gutspear, and Murdered Child constantly wrangling with each other for territory. The current holder of Urgir, Grask Uldeth of the Empty Hand, has discovered the value of trade with less beefy races, and your average PC can walk the streets in relative safety... most of the time. Other locations of note include the Brimstone Haruspex, where orc clerics huff volcanic gas to predict the future, and the Foundry, where and I quote: "crazed orc engineers known as Steeleaters remain neutral in order to sell their bizarre siege weaponry to all sides." Green really iz da best, innit?
Brevoy
Asshole nobles struggling for dominance.
Cheliax
Motherfucking DEVIL NAZIS.
Druma
Jewish Scientologists. Contrary to expectations, not dwarven, though there is a substantial dwarven minority.
Five Kings Mountains
When the dwarves forced their way to the surface, they popped up here mostly. Funnily are neighbors with the elves and the not!Jews, as well as the not!Americans.
Galt
VIVE LA REVOLUTION!
Geb
Fuck yeah Lich King.
Hermea
Council of Wyrms: The Nation.
Irrisen
Russian ice witches. Founded by Baba Yaga who shows up every 100 years to kidnap the current queen and install a new daughter on the throne.
Isger
Cheliax's bottom bitch. Only notable because their flag has a barely-disguised swastika on it.
Jalmeray
Little India.
Katapesh
Slavers and drug dealers ruled by a mysterious and alien race.===
Kyonin
Typical elf kingdom. Been fucked over by a demon who has blighted a huge swath of the south.
Lands of the Linnorm Kings
Vikings and weird dragons.
Lastwall
Crusader state that fights Orcs and Vampires.
Mendev
Another crusader state, this one fights demons. It's queen is over 100 years old but looks to be early middle aged due to a youth potion they buy from Thuvia.
Mendiogalti Island
Island of assassins who venerate a giant red praying mantis god. They can and will murder anyone but sitting monarchs.
Molthune
Fantasy Prussia. Recently lost their northern lands to a bunch of Robin Hood wannabes.
Mwangi Expanse
Home to intelligent gorilla men and a super ancient empire of black men who lived in flying cities making the saying "We wuz kangs" sorta true for Pathfinder.
Nex
Bunch of archmages who have royally fucked up their lands in a massive war with Geb to their south, almost single-handedly making the nation of Alkenstar in the process.
Nidal
Client state to Cheliax, they are basically Clive Barker's Cenobites (think BDSM people who love hard piercings and spiked chains).
Nirmathas
Basically this is Robin Hood's Sherwood Forest.
Numeria
Conan meets science fiction, so expect super buff barbarians throwing spears at giant metal scorpions with laser eyes. Hard core as fuck.
Osirion
Literally Egypt if the Mummy movies were documentaries.
Qadira
Fantasy Turkey/Arabia. Have warred with Taldor and for a while ruled Osirion. May or may not be on the verge of a civil war.
Rahadoum
A country so fucked over by the gods that divine magic and worship is outlawed. This no-doubt displeases the gods but they continue their machinations in secret via espionage clerics.
Razmiran
Ever play a game with an edgelord who always wants to be the super-bestest at everything and the GM just capitulates to their every whim and gives them a kingdom which they rule worse that North Korea and say everyone should worship them as a god? Well, that's pretty much this country. Previously part of the River Kingdoms, broke off a few years ago because said "God-King" converted a bunch of idiots.
Realm of the Mammoth Lords
Ever want a low fantasy caveman game that still fights witches, giants, demons and more? Go here.
River Kingdoms
A vast territory of constantly rising and falling petty kingdoms. All neighboring countries claim some bit of it but can never hold it long due to various reasons. So it's the Balkans of the setting.
Sargava
Technically a colony to the devil-worshipping assholes in Cheliax, they are effectively independent thanks to the massive fuck-you hurricane and pirates to their north. The local Mwangi people are little better than slaves and may be plotting to overthrow dem white bois.
Shackles
Pirates of the Caribbean. "Ruled" by the Hurricane King, every island and small stretch of land is claimed by some pirate or pirate group.
Sodden Lands
Previously consisting of two small kingdoms that thrived on prophecy, when Aroden died and prophecy pretty much failed followed by a massive hurricane that would make Katrina look like a small breeze, they collapsed and this is now just ruins and swampy, marshy lands. So yeah, Louisiana on a bad day.
Taldor
Has overtones of the Byzantine Empire and British Empire. Stagnant, decadent, corrupt. The grand prince hires vikings as bodyguards. Once rules much of the world but has become a shadow of it's former self.
Thuvia
Barely held together because the small cities in this realm produce the single most sought after magical item. No, not girdles of gender-swapping. I swear to... No, they make a potion that reverts the drinker to the prime of life. Consume it often enough and you basically can be immortal. Only a few batches are made each year and the prices are exorbitant.
Ustalav
I vant to zuck your blood! Take every fantasy gothic horror trope and dump it here. You got vampires, zombies, werewolves, liches, hags, voodoo, Cthulhu, witches and everything else.
Varisia
This is the main setting of the main setting. Vast wild lands, a few small cities at the edges, massive ruins to explore, goblins to kill, gypsies and more. Most of the adventures paths either play completely here, start here or at least have ties here.
Worldwound
Aroden, god of humans, made a lot of enemies in his day before he died. One was a giant insectoid demon lord. When he bit the bullet about a hundred years ago, the demon lord saw his chance and tore open a new gaping hole into the world to fuck. In constant war with Mendev and for the most part leave Numeria and the Mammoth Lords alone because why would you fuck with alien tech and guys who fight on mammoths?
Lands Beyond the Core Setting
Paizo, still wanting even more kitchen sink fantasy and wanting to emulate Forgotten Realms, have other continents and lands beyond the core setting.
Arcadia
Well they needed a place for the Americas. Notably the vikings from the Lands of the Linnorm Kings think of it as a kind of paradise and their rulers have a settlement on it in an allusion to Vinland from viking history.
Azlant
Atlantis by another name. Home to the first human empire that was uplifted by the aboleths, was destroyed by the Starstone when the aboleths thought humans were getting uppity.
Casmaron
What happens when you mix India, the 'stans and the Middle East? This. Vast swaths of largely unruled or ungovernable lands but also two massive "empires", one being a Persian/Ottoman expy, the other being fantasy India.
Crown of the World
Connects Avistan (Europe) to Tian Xia (East Asia). Has a few eskimo-like settlements and Cthulhu horror themes going on here.
Darklands
Paizo's Underdark. Drow, Svirneblin, Duergar and all the tropes therein.
Sarusan
Mysterious land of deadly terrors which is clearly Australia. Australia is bad enough, who the fuck knows how scary it would be with fantasy elements.
Tian Xia
Has all your classic East Asia fantasy tropes going on here. Decadent empires, eastern dragons, monks in monasteries learning kung-fu, mystical monks meditating under waterfalls, Studio Ghibli creatures running around, Naga, Oni, Mongols, and samurai.
Gods of Golarion
Races of Golarion
Being effectively Dungeons & Dragons 3.75, Golarion is absolutely crawling with races. Your D&D standards are here, but there's also an ever-growing array of races, from monstrous humanoids to ones lifted from real-world mythology to even homebrewed races.
The Standards
Human: Bog-standard human, following in the best D&D traditions by having different nations with different hats to wear.
Dwarf: Originated in Golarion's Underdark, migrated to the surface in the legendary "Quest for Sky" centuries ago.
Elf: One of the planet's oldest races. Buggered off through magical gateways to another planet during the worst of the Starfall disaster, then came back a few centuries ago.
Halfling: Pretty much your standard stunties, barring the fact that they're very popular slaves throughout the Inner Sea region.
Gnome: Fey who migrated to Golarion from The First World, then found out that without regular stimulation, they undergo something called "The Bleaching" which drives them mad and painfully kills them.
Half-Elf: Pretty much your standard half-elves.
Half-Orc: Extra emphasis on the "you were probably born from rape!" backstory.
Monstrous Humanoids
Goblin: Doubles down on the Chaotic Stupid aspects; love fire, really good singers, absolutely terrified of dogs, horses and writing.
Orc: Driven up from the Underdark by the dwarves, who they used to war with. Really double-down on the Always Chaotic Evil aspects.
Kobold: Pretty much the D&D iconic version.
Hobgoblin: A militaristic race descended from an experiment to magically mutate goblins into slave-soldiers to fight against the elf empire; their creators were killed, but the hobgoblins were complete, and now they don't have an off-switch.
Foreigners
Because Golarion has lots of "not!X" countries, there's both a "not!India" (Vudra) and a "not!Orient" (Dragon Empires), each of which has some fairly unique races native to it.
Kitsune: Your standard mischievous fun-loving shapeshifting fox-folk.
Nagaji: A race of serpentfolk bred as slaves by the nagas; they're quite content in their servitude.
Samsaran: Spiritually enlightened blue & white-colored humans who continuously reincarnate.
Vanara: Friendly, sage-like monkey-people.
Sci-Fantasy Races
Pathfinder's mapped out the star system that Golarion comes from, and in best pulp fantasy fashion, that means that you can play androids and aliens in this setting too.
Android: Look like humans with pale, silver-tinted skin and circuitry that lights up like science-tattoos when they use their powers. Most common in Numeria, as they are born out of "creation forges" left behind when the starship crashed.
Kasatha: Four-armed humanoids who don't remember what world they came from. Favor dual-wielding bows.
Lashunta: The natives of Golarion's equivalent of Venus; antennaed humanoids with psionic powers and extreme sexual dimorphism - men look more like dwarves, women look more like elves.
Triaxian: Pointy-eared aliens whose planet undergoes an extreme orbit, leading to centuries-long summers and winters, and thus the species is divided into "Summer Generation" and "Winter Generation" subspecies.
Real-Worlders
The least common race group, so far, these are critters taken from non-D&D fantasy sources, including several Lovecraft races and beings like the Orang-Pendek, a real-world cryptid that's basically an Indonesian Sasquatch.