Orianna Runes explained
There's one set of runes for Orianna on patch 14.19 that is the clear favorite for LoL players and pros alike. The best Orianna rune paths on the position 
Mid are 
Sorcery as the primary path and 
Inspiration as the secondary path with a pick rate of 62%. Besides picking runes on Orianna you should learn how to play Orianna and if you are interested in pro matches take a look on how a pro builds Orianna. If you want to discuss 
Orianna then you should visit the champion subreddit.
Orianna runes from primary path
Sorcery empoweres abilities of Orianna and increases the available champion resources. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Arcane Comet is the best keystone rune to run on Orianna. This keystone rune adds more damage to your abilities and increases your power in the laning phase. Other primary runes on Orianna are 
Manaflow Band, 
Transcendence and 
Scorch.
This is usually followed up by taking Manaflow Band for additional mana and mana regenaration. Transcendence for some more Ability Haste. Scorch increases your control in the early game.
Orianna runes from secondary path
When it comes to your secondary path, most Orianna players prefer to go with Inspiration. Inspiration opens creative opportunities on Orianna troughout the match. On the Inspiration path, the best runes for Orianna are Biscuit Delivery and Cosmic Insight.
Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes. Cosmic Insight grants summoner spell and item haste.
FAQ for Orianna Runes
Which is the best keystone rune on Orianna?
The best keystone rune on Orianna is Arcane Comet. This Orianna runes setup is then referred as Orianna Arcane Comet.
What runes does Orianna use?
Runes from the paths Sorcery and Inspiration are the most used runes on Orianna. For the exact pick rates of Orianna runes used, you have to study the rune distribution presented.