Earth isn't the only birthplace of humans in the Star Wars universe. One could surmise that God created humans somehwere else first, or that he seeded several planets with human existance just in case one "experiment" failed, then a nother would still be there to thrive. It could also be argued that the "humans" in Starwars aren't "Human" but are humanoid. They would technically be Corellian, Naboo, or even Alderaanian where we are technically Terran Humanoids. We lazily call ourselves human as there is no real evidence that humans exist anywhere else but on Earth. Another arguement might be made that it was a long time ago in a galaxy far far away and that the same rules just simply don't apply there as they do here in our galaxy and time line. We discover new civilizations and ruins everyday, whose to say we just haven't run across any of their ruins yet.

Perhaps a spacefaring extragalactic supercivilization from very ancient times decided that it was fitting to abduct early humans, take them for an intergalactic ride, and place them on the planets they've chosen in the Star Wars galaxy. Then either the records of such a happening got destroyed when during a massive upheaval that civilization broke up into smaller ones, or they weren't from the Star Wars galaxy in the first place and left shortly after, never to return.

While jenniferprofit's answer is sufficient, I think it could have been better. First off, the word "Terran" is a product of science-fiction, and while I like the notion of classifying our race as something other than the tired "earthling" the fact is that we're simply called "human" and that's it, nothing lazy about it. Secondly, Star Wars uses the word "human". I'm not the biggest Star Wars geek out there, but I know of two sources- Star Wars: Knights of the Old Republic (video game) and A New Hope: Special Edition (in which Han Solo says to Jabba "You're a wonderful Human Being" sarcastically). But if you're going to go into this question, you might just as well relate the question of why are they speaking English? what are the odds of that? And the best answer is that the movie is in fact a translation to English from Galactic Basic. Other alien languages, such as Huttese and Shyriiwook, have been left untranslated for dramatic effect. This would then explain why they use the term "human" if it is in fact a translation of the Basic word of like meaning. It's all about understanding. One might compare this to Native Americans... when English-speakers first came across a Navajo, they might ask what he calls his people, he will say Navajo (their word for "people"). If we met another planet of homo sapiens, odds are they would not call themselves human, but the same word in their own tongue. It should also be noted that while there are "humans" in the Star Wars galaxy, there are many races who are not human but can be mistaken as such: Aquar, Arkanians, Bimm, Bortrunians, Bornecks, Brigians, Chev, Chiss, Epicanthix, Etti, Ferroans, Firrerreo, Galacians, Gen'dai, Gerans, Grannans, Hapans, Hrakians, Khommites, Kiffars, Langhesi, Massassi (Sith), Miraluka, Mirialans, Nagai, Omwati, Qiraash, Ruusanians, Sernpidalians, Skeebo, Sorrusians, Stennes, Teevans, Theelin, Tof, Ubese, Umbarans, Vultans, Wroonians, & Zeltrons Anything else that looks human, probably is- regardless of wether it's Tatooinian, Madalorian, Naboo, etc - the equivalents of American/Mexican/Canadian/etc. They are still human, but may have a specific name and language from their home planet.

It's just a fictional story! How do the light sabers stop at their ends? Why do we hear the x-wings and tie fighters screaming around space? What the hell is Yoda? It's an imaginary universe! I think that George Lucas used humans as the main characters so we could relate to it. It does seem real. Real people with real problems and real villains that fight real heros. If aliens were used as the main characters I don't think it would've had such a following because it would be a total fantasy. But because humans are used it seems more believable and has a sense of realism to it. But still, it's just a story so it can have what it wants in it. As soon as some one invents a real light saber, could they let me know.

George Lucas adapted much of the Star Wars Universe from Isaac Asimov's Foundation series. In those novels, the Galactic Empire was inhabited of humans only, with a Coruscant-type capital world in Trantor. In later books such as "Foundation's Edge" and "Foundation and Earth", Asimov linked the Foundations mythos to his Robots mythos, whereas the protagonist of the novels went on a journey to find the primeval Eden world of human kind. This would turn out to be Earth, long forgotten by 40,000 years of galactic history. In Frank Herbert's Dune series, Earth has also become long forgotten importance after 10,000 years of galactic empire building. Battlestar Galactica follows a slightly different premise, citing Earth as the 13th lost tribe of Kobol, and the ultimate destination of the Galactica fleet that was fleeing war with the Cylons. Again, the endpoint of the books involves discovering this ancient mystery, and thus linking science fiction to our contemporary reality. In these cases, Earth's position was central to the mythology and cosmology of the galaxy spanning civilizations. However, as the Star Wars Universe is set "a long time ago, in a galaxy far far away", it is possible to surmise that Earth was originally colonized by humans that were able to make the jump from that galaxy to ours. Many science fiction novels contain this as their premise, including Star Trek, where in a pivotal episode of Next Generation (#146 "The Chase"), all humanoids were found to have the same ancestor from 4 billions years ago. This is an incredibly ancient origin for a human species that has only arrived in its current form (as well as that of Vulcans, Romulans, Klingons, Cardassians, etc.) 200,000 years ago. Many other works of science fiction tell similar origin stories. Ursula K. Leguin's Hain cycle focusses on the anthropology of divergent human civilizations, found scattered on many worlds. The progenitor race is never made clear, although the Hainish, the oldest and wisest of the races, are said to have seeded the planets with humans. In terms of Star Wars, maintaining the mystery works well, as it generates the controversy that fuels fan speculation and interest.

Well, just think about it. They wouldn't have actors in costumes that looks like aliens would they? They would most certainly use humans. So for instance, on the mustufar battle scene, imagine how that would of looked like if the actors weren't humans.

I've been told that it was not realy a long time ago. It is obi wan or some starwars chracter telling of the past. so its about the future and some guy is telling about further back but not before our time.

If you believe in the Adam and Eve story, it doesn't make sense. But because this is Science Fiction- he decided that humans had been around much longer than the bible states.

because it is a fictional story about a fictional place with a fictional galaxy...

shhhh. don't spoil the fantasy. LOL

I can't believe there are people who are actually trying to justify this question with an answer.

There's a group that have been studying this for a while and the interaction between Earth and the Star Wars universe seems to be more than fiction: www.ifstarwarswasreal.com The above website documents the evidence that Star Wars could actually be real.

its a long time a go in future (what, are you thinking about lightsabers in past) old knights with light sabers and have a space craft?!?

Maybe it's happening/did happen in another deminsion.

Because it's fiction.