He wouldn't be able to. But he should be able to.

That's actually an excellent question... What does it mean to be "worthy" to wield Mjolnir?
 
Spider-Man is Brave, honorable, selfless, compassionate, and so on and so forth...  but does that fit the bill?  Spider-Man has always been my favorite comic book super hero; he probably always will be....But perhaps the fact that he will never kill, under any circumstances, makes him 'not worthy to wield Mjolnir' in the eyes of whoever made the rules.  We know that Thor, on occasion, has killed.  Perhaps one has to be willing to kill when necessary.  Perhaps one has to be completely confident in their own abilities and Spider-Man has always doubted himself.  Thor is a natural leader and people automatically follow his lead; I'm sorry to say that the same cannot be said for Spider-Man...dang it...
 
So this raises a question.  Who else in the Marvel universe WOULD be worthy?  Captain America?  Dare Devil?  Spider-Girl?

If Odin allows it, then Spider-Man should be able to wield Thor's hammer. Especially if his is the last superhero standing. A good example would be to transport him from Earth-616 to Earth-2149 to help lead the surviving members of the human race to safety through a portal that would take them to an alternate Earth. Since Odin never appeared in the Marvel Zombies, we could assume that he was not Zombified. So, if Spidey is able to use the power of Mjolnir, he could use it to summon Odin in his place. 
 
Also, here is a picture of Spider-Thor from The Marvel Adventures series

Depends on the writer, but I'd say no. Walter Simonson's reasons. 

That's actually an excellent question... What does it mean to be "worthy" to wield Mjolnir?  Spider-Man is Brave, honorable, selfless, compassionate, and so on and so forth...  but does that fit the bill?  Spider-Man has always been my favorite comic book super hero; he probably always will be....But perhaps the fact that he will never kill, under any circumstances, makes him 'not worthy to wield Mjolnir' in the eyes of whoever made the rules.  We know that Thor, on occasion, has killed.  Perhaps one has to be willing to kill when necessary.  Perhaps one has to be completely confident in their own abilities and Spider-Man has always doubted himself.  Thor is a natural leader and people automatically follow his lead; I'm sorry to say that the same cannot be said for Spider-Man...dang it...  So this raises a question.  Who else in the Marvel universe WOULD be worthy?  Captain America?  Dare Devil?  Spider-Girl?

no.

Anyone who is worthy to weild Thors hammer.

If Spiderman for even one moment is worthy he can weild Thors hammer.

If he were worthy, but man that would make an awesome story arc.

@Timandm said:

That's actually an excellent question... What does it mean to be "worthy" to wield Mjolnir? Spider-Man is Brave, honorable, selfless, compassionate, and so on and so forth... but does that fit the bill? Spider-Man has always been my favorite comic book super hero; he probably always will be....But perhaps the fact that he will never kill, under any circumstances, makes him 'not worthy to wield Mjolnir' in the eyes of whoever made the rules. We know that Thor, on occasion, has killed. Perhaps one has to be willing to kill when necessary. Perhaps one has to be completely confident in their own abilities and Spider-Man has always doubted himself. Thor is a natural leader and people automatically follow his lead; I'm sorry to say that the same cannot be said for Spider-Man...dang it... So this raises a question. Who else in the Marvel universe WOULD be worthy? Captain America? Dare Devil? Spider-Girl?

I agree. Spiderman has all the right values except for being able to kill. Which is a weakness cause part of being a leader and being worthy I imagine is being able to make a difficult choice like that. And I don't see anyone who doesn't naturally command respect wielding the power of Thor either.

I would say the features that keep Spider-Man from being able to weild the Hammer are his guilt and his self-doubt.

@Justin_Credible said:

@FadeToBlackBolt said:

He wouldn't be able to. But he should be able to.

Pretty much this.

Yep.

Thor's Mjolnir is enchanted by Odin so Mjolnir will always be magically bound to THOR, but if anyone needs the help if he is "worthy" then he can wield the hammer of THOR in desperate needs.

There are many superheroes who actually surpass the definition of "Worthiness" like Superman, Spiderman, Captain America. These three heroes have more good qualities than THOR, they are always remembered for their self-sacrifice in there respective universe.

Below is information about worthiness from one blog, I have copied it here and also provided the link so everyone can check it:

Spider-Man is certainly self-sacrificing, arguably even more so than Thor. He lives by the adage "with great power comes great responsibility", and Mjolnir is obviously a great power. However, Spider-Man is more motivated by guilt than a purely altruistic nature, and I think that is what takes him out of the running to lift the hammer.

If there is one character around who I personally think would be worthy, it's Ben Grimm. Ben is a hero's hero, sacrificing his own happiness to turn back into the Thing when others need him. He has dedicated his life to helping others as a member of the Fantastic Four. His never-say-die attitude is legendary (eg. his battle with the Champion). So why isn't Ben worthy? Quite recently we saw him try to lift the hammer and fail. I think the reason is Ben's own self-loathing and insecurity about his appearance. He doesn't have the self-confidence/esteem needed to wield Mjolnir.

This brings me to Captain America. Cap certainly embodies everything discussed thus far, without the guilt or self-loathing to weigh him down. Confidence is certainly something he doesn't lack. Cap has lifted the hammer on two occasions now, and it is worth noting that both times he has not undergone a transformation into a Thor-like being. My feeling here is that while Cap had need of the power, he has never intended to take it from Thor, rather he has borrowed it.

This leads me to the conclusion that to lift Mjolnir, you must have need of it. Beta Ray Bill certainly had a need, as his world's champion against Surtur and his hordes. Superman managed to use it once, and that was when the entire DC and Marvel universes were at stake. When there was no longer a need, even though he was just trying to return it to Thor (in far less perilous circumstances than when Steve did the same), Superman could not lift it.

Which ultimately leads us to why isn't Superman worthy. Again, this comes down to need. Superman doesn't need the power of Thor, he is just as powerful on his own. He exemplifies many of the same characteristics as Thor, but since he has no need of the power of Thor, he cannot lift the hammer either.

And before anyone asks about Wonder Woman, as far as I know the only Marvel/DC crossover that is actually in continuity is JLA/Avengers. That being said, you could argue that Wonder Woman was fighting for her entire universe, and since she lost to Storm (due to fan voting) she obviously could have used the power boost.

You can read above article at: http://doeswhateveracomicsblogcan.blogspot.in/2011/11/if-he-be-worthy.html

Spidey saved reality Time and Space in Some Times and hé did it with out the hammer and how Many Times did Thor save reality spidey 1 Thor 0 Who sayed with great power comes great responsibility spidey 2 Thor 0 Who is in the Avengers spidey 3 Thor 1 Who passed the beyonders test spidey 4 Thor 1 Who is a god spidey 4 Thor 2 Who defeated 6 or more villans in the same Time spidey 5 Thor 2 Spidey is more the worthy

Pure of heart. Noble of mind. And having a warriors courage. Oh and humility of course. The definition of pure hearted is "(of a person) without malice, treachery, or evil intent; honest; sincere; guileless". While the definition of Noble is "having or showing fine personal qualities or high moral principles and ideals."I just basically boil it down to two things. Doing the right thing and doing it for the right reasons. Because fiction constantly has the heart and the mind at odds with one another. After all someone with good intentions can still hurt others. And a person with a noble cause can be doing it for the wrong reasons. So you need both in perfect balance. And lastly the definition of courage is not to be afraid but to do things despite the fear. Or as the google definition says "the ability to do something that frightens one. strength in the face of pain or grief."

He is definitely worthy of wielding the Mjolnir Hammer, but the reason he can't is because he's not willing to take a life when it's necessary. For example, Miguel O' Hara the Spider-Man of the year 2099 can use Mjolnir and the reason why, is because he is willing to kill someone when he has to, unlike Peter Parker.

@fromapov: Since when has it ever been confirmed that you need to be willing to kill to use the hammer? Even one of the power pack kids has been seen lifting that thing and they are just children. I don't think the killing is a factor. Yes it's marvel adventures but the Enchantment there is the exact same as in 616, only the worthy may lift it and a 15 year old boy working to protect his family was worthy. https://imgur.com/gallery/2IIPV