Short answer is yes, you should be able to do this by just putting the dependencies where lein expects to find them and then it will use them instead of going out to download them. That said, I've never tried this.
It looks like the answer to this question pretty much points to how to do it:
- Run
lein deps
on a machine that is connected to the Internet - Copy
$HOME/.m2/repository
to your server
and that should take care of it. However, I have not tried this, so there may be some problem with this method that I have not foreseen.