Is it possible to solo Baron Nashor?

Yes, its possible to do so assuming your hero has good items. High level runes are almost essential as well, so best to try this once your summoner is at level 30.

Heroes with summons seem to be a good way to solo Nashor; for e.g.

Zyra:

Shaco:

These have the advantage of basically turrets that keep firing at him while you can try to back off and heal. Other champions who can solo the Baron:

Tryndamere:

Ashe:

and well, pretty much any well-fed lvl 18 champion.

The best way to ninja solo Nash safely is with more life steal than you loose

It do it frequently with :

• Fiddlestick (14)(Blue + 400 AP)
• Tryndamere (Good critical + Bloodthister)
• Olaf (Wiggle)
• Jax(gunblade + Wriggle)
• nocturne (Wriggle)(nahs gives free AS doing spells on the shield ;-) )
• Sion (AD + ult)
• Xin Xiao(Wriggle)
• Nunu jungle with Spirit of the Spectral Wraith and Glacial Shroud + Blue Solo Nashor at 15-20 mn maxing Q you just need someone to take some hits for you

Think a Nunu + Vayne//Kog can do it pretty fast too ;-)

Good luck trying that. Be careful to not be warded and that the other jungler is always visible. Giving a free nash on a ninja nash is pretty ugly.

I guessed its mostly AD champions that will be able to solo Baron, even if they are AD champions, they must fulfil two requirements (at least i believed)

1) farmed adequately enough for good powerful items (e.g The Bloodthirster, Black Cleaver ..)

2) the abilities of the champions, I have tried Xin Zhao before and with his passive ability to gain life and his increase attack speed he is able to match the dmg output of Baron by stealing back some life. Others I have tried without much success.

The best mix for a solo will be good items and abilities that can either stun or increased attack speed ( XZ seems to have both, the triple strike and his increased attack speed) . As most tanker champions can't deal out much dmg and even tanker heroes cant tank that long against baron.

I would imagine that any AD champion with at least 1.0 attack speed and 6 farmed Bloodthirsters should be able to solo Baron, but most builds that you'll see in actual gameplay won't be suitable for soloing him. Duoing is another story.

AP Carrys with spammable spells (cassio, karthus, Ryze, Zyra) have an easy time soloing Baron.

Bruisers/ADCarrys can do so, but its somwhat harder due to Baron Nashor debuffing the AD of the champ who tanks his attacks.

Jax is a really good champ for soloing Nashor.