Jedi are telekinetic space ninja. You can tell this is science fiction from the word "space."
No, Jedi are telekinetic space wizards/knights. You can as a prelimenary classification stick 'Star Wars' into fantasy from that fact alone. Further analysis only reinforces that point.
The basic plot of 'Star Wars' is so pure fantasy as to be a cliche.
A farm boy living in a remote part of the empire is recruited by a wizard to rescue a princess in distress. Along the way he discovers that he is actually the long lost heir of a mighty Lord, knight, and sorcerer. After some training in sword and sorcery, the mentor Wizard dies, and the young farm boy slays the terrifying dragon which is threatening the good people of the empire using his training and knowledge of the beasts secret weak spot.
This is pure fantasy, and the dressing of the setting in the superficial tropes of science fiction just barely disguises that fact.
We've argued this point at EnWorld several times before. I'm not sure we ever found a perfect definition, but I still stick behind mine.
Fantasy is that branch of fiction which addresses the question, "What is the meaning of good and evil?" by imagining abstract concepts in tangible form. Science-fiction is that branch of fiction which addresses the question, "What does it mean to be human?" by imagining things which are not human and comparing and contrasting those things with humanity.
'Star Wars' has some elements of science fiction, such as the droids, but its not really interested in this question and pretty much handwaves the question of the humanity of aliens and robots or how aliens or robots might be different than humanity. The real focus of the story is on the meaning of good and evil and how one moves between these two states. It is a story of falls and redemptions that spends alot of time talking monologuing about essentially theological and ethical matters. This puts it firmly into the fantasy genera. The fact that is also a sword and sorcery drama at heart and that it never uses or addresses any scientific questions or terminology also ought to be a big clue.
The reason I like my definition is that it comes much closer to classifying everything where we instinctively classify it than any other definition I've come across. 'Star Wars' is an example of an outlier, but once you get past the idea of spaceships and laser beams as a distinctive feature of science fiction and look at the actual story, even that objection to my definition tends to go away. In particular, the problem with defining science fiction by things like 'spaceships' and 'laser beams' is that such a definition tends to assume 'spaceships and laser beams' as a necessary feature of science fiction, something that is certainly not true.