Generally no, the lowest version of OSX you can install is the version that was installed when you first purchased your mac.
Not necessarily the case here, though, as the base logic board is same as early 2011, sharing the same EFI updates. So it may well work, but you'll need the snowleopard disk specifically meant for the early 2011, as they never merged it's version into the general line.
One would have to try with a cloned drive with the latest Snow Leopard on it to know for sure, it'd be a quick and painless way to do it.
As a general rule of thumb though, the earliest version of OS X you can stick on a Mac is the one the computer came with.
iMacDragon is correct and I can confirm 10.6.8 working on the late 2011, but only the lower end graphics. Not to say it won't work, but you will have to wait til someone tests it.
I got a set of early 2011 DVD's which I used to install 10.6.6 on my late 2011 low end 15".
I did not install the EFI 2.3 update before, I think the new EFI update might limit this, since it 10.6.8 and up.
Ok here is the latest! First some background. A cpl of months ago i bought an early 2011 base 13" mbp. It came from the apple store online as a refurb and had lion on it. I took it to the genius bar and 25 minutes later had sl on it. No problem. I just picked up another base 13 mbp in an open box deal at bestbuy -- a steal at $800. It had lion. I took it to the genius bar, came back an hour later and they couldnt do it. Seems it was a late early 2011 -- shipped by apple in late july 2011 -- and the firmware had been updated ONLY for lion. It really pissed me off cause i have one major pgm that i use that is incompatible with lion. Ms word 2004. I will now have to upgrade On the other hand while i havent spent extensive time with the new lion based mbp yet i do like it. So far lion is VERY fast. Some things are a bit hard to discover or get used to -- mail has some changes and safari does too. But overall i like it. But i will keep my other macs on snow leopard.
I moved my SSD with SL installed from my 1st gen Mac Pro to my late-2011 17" MBP and it worked perfectly.
I then used the copy of Lion I'd downloaded for my late-2010 MBA and created a bootable USB and upgraded the MBP.
All works perfectly.
So yes I think SL from any source will work fine.
It really pissed me off cause i have one major pgm that i use that is incompatible with lion. Ms word 2004.
Ms word 2004..