|Champion||Background||Strategy||Skins & Trivia|
- Irelia was designed by Ezreal.
- Irelia's swords stab her as she dies. Whether Irelia does this out of or due to losing control of her blades is up to debate.
- The floating object behind her head is the "Mantle of Decorum", which is Ionia's highest decoration.
- Irelia bears a resemblance to Melia Antiqua, a character from who has a similar outfit as well as hair color.
- Irelia was one of the champions chosen for the Ionian pool available during the 2010 Ionian Versus Noxus Grudge Match. However, she was not one of the selected champions.
- It has been hinted that Irelia's brother Zelos is possibly being made into a champion and is currently in development.
- Irelia, has among the highest potential tenacity stat in the game, capped at 64.9% (40% from her passive, granted at least 3 enemy champions are within her sights, 15% from the Tenacious mastery and 35% from any tenacity item in the game, i.e. after being calculated with diminishing returns). Thus, the duration of almost all crowd control effects in the game can be cut by more than half against Irelia.
- Previously, Zac could achieve 86.18% tenacity, the highest, while using Let's Bounce!, Tenacious and 35% from tenacity items in-game. However, this only lasts for the duration of Let's Bounce! and so Irelia's is more reliable. This is no longer possible after the tenacity boost from Zac's ultimate is removed.
- Irelia is the focus of a LoL meme "better nerf Irelia", in which Morello determines that a certain champion is currently overpowered, but chooses instead to nerf Irelia, due to his numerous alterations to her skillset.
- Irelia received nerfs one day before her release because Morello said she was too "annoying to play against."
- ricklessabandon stated that Irelia is somewhat similar to a lich, and her weapon acts as her phylactery. 
- The naming of her style, "Hiten Style", her backstory, and Xypherous' confirmation show Irelia is based on Kenshin Himura of Rurouni Kenshin. 
- Her French jokes are references to the character of from the eponymous French film.
- Her joke "My blade is not only precise, but totally gnarly" references that she rides her weapon like a surfboard and "gnarly" being a term used by most surfers to tell if something is cool or good.
- Irelia shares a quote with Garen: "Forge Onward."
- Irelia shares a quote with Ezreal, Annie, Thresh, and Evelynn: "This way."
- Aviator Irelia is a reference to , the first woman to fly solo across the Atlantic Ocean.
- Chinese Nightblade Irelia is similar to the cover, both Ezio and Irelia bearing the hidden blade on both of their arms and making the same stance.
- Nightblade Irelia also bares similarities to Marvel Comic's character "Blackwidow" due to the black outfit and red belt buckle.
- Nightblade Irelia shares a striking resemblance to Silverfang Akali in design.
- Soraka was responsible for reviving a nearly deceased Irelia during the Noxian invasion of Ionia.