Hey there and welcome to my small Leona AD Jungler Guide.
I've racked up 2 builds of which one's very armor heavy, based on tankiness.
And the other is a whole lot of madness, considering Leona's abilities and heavy AD, aside from Tankiness.

The 1st one has been tested for around 15 games, and it works reasonably well, as long as you level quickly in the jungle and don't consider ganking until level 4.

The 2nd build is much more insane and effecient, to my calculations. And even though I haven't tried it out, I'm sure it'll be much stronger than the 1st one.

Note how I've added chapters about each important section of the two builds. Although the Masteries, Runes and Abilities are the same, it's the 6th Item Chapter that's probably the most interesting. The Notes in both builds will be pointing towards the appropriate chapter names.

Furthermore, the 2nd build has a special 6th Item Chapter, which is the most important bit, the rest can be seen as obvious or will be discussed online or in the comments.

Thx again for visiting my build, it was a pleasure to make.
Good luck out there, Summoner! ^^
~ThePersister

This build has been posted on Mobafire for an easier distribution to friends and summoners across the League. Therefore, it does not grant a whole 10-20 chapters about Leona and why this would work correctly.

However, I can tell you that I'll try to update this build to be the most efficient at any given time. And that, so far, it contains the best two ways to play Leona Jungle.

Getting a leash will speed up your jungle by as much as ~150%, so please consider asking your teammates for better odds.

The 1st is a very Armor heavy build, but does not contain all that much Magic Resist, therefore, it might not be good against very Heavy AP TeamComps.

The 2nd is a very Health / AD heavy build, and it will pack enough punch and sustain to take on most fights from early to late game.

I'm not the greatest jungler, nor the greatest Leona player, but I can tell you that it's a blast to come out of the jungle and throw down all of Leona's utility.
The only thing I regret about this build is that Leona's Passive is entirely useless in the jungle itself, only once she ganks, you'll feel her passive again. But it's worth it.

Good luck out there, have fun!
And don't forget to bring me feedback in case you've got something good ;3

These are my Global AD Jungler Runes, granting some good AD, but HEAVY armor for any jungler, it helps sustaining in the jungle at the start and with lvl 1 engages, since some junglers, like Leona, can make invades more potential with their lvl 1 ability.
Although note that it's NOT advised to avoid picking Elipse, because it will influence her lvl 1 clear drastically, for the worse.

One does not have to explain the power of the W waveclear, since it's AoE and has the most damage at early 1 and later levels. Aside from that, the Q is next on the list with it's heavy stun which is very usefull against monsters and players. Furthermore the E you only need 1 lvl in it to gank, and it doesn't deal a lot of damage to monsters, nor can you leap to them with it, so for Leona Jungler it has the lowest priority. And obviously you'll want to get your ult at any given time you can.

Note that lvl 4 ganks are strong, but lvl 6 ganks are devastating.
Leona ganks will work fine, but they'll do the best if you can land your E (lunge) on your victim.

These are the Amumu masteries by the pro player "TheOddOne".
And apparently they work just fine on Leona.

Notice that the Bladed Armor mastery in the Defense tree is VERY valuable to Leona's Clear, as she only needs 2 Elipses and the wolves will kill themselves thereafter (in case she didn't get a leash)

This one's a toughy!
From top to bottom, most preferable to least preferable:
- Randuin's Omen grants you even more activatable CC, gives you more Health as well as slow enemies
down who try to turn around and kite you whilst running away, and it allows you to flee better
from adcs.
- Frozen Heart is a Very Nice item in terms of Armor and CDR, and although it doesn't top Randuin's
Omen, it's still a horribly good item on Leona, so if you come across Heavy AD teams and you need
to spam your spells Even more, then Frozen Heart might be the way to go.
- Mercurial Scimitar if you want more Damage and you're getting hit a lot by Magic Damage and/or
CC.
- Maw of Malmortius is a reasonable item, but its passives would go to waste, most likely,
especially the percentage extra AD one.
- BT is just BT.
- Thornmail if the enemy Adc is fed or you just want to annoy them.
- GA if you're somehow dying whilst you could do more after death, which is unlikely.
- Last whisper if you really like Armor pen, but it's probably not gonna help.

There you go, choose wisely! ^^